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'Doug214' == Outdated reference: A later version (-04) exists of draft-york-vpoll-03 Summary: 1 error (**), 0 flaws (~~), 9 warnings (==), 4 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Apthorp 3 Internet Draft DHL Express 4 Intended status: Standards Track C. Daboo 5 Updates: 5545 (if approved) Apple Inc. 6 Expires: March 17, 2016 M. Douglass 7 RPI 8 September 14, 2015 10 Task Extensions to iCalendar 11 draft-apthorp-ical-tasks-01.txt 13 Abstract 15 This document defines extensions to the Internet Calendaring and 16 Scheduling Core Object Specification (iCalendar) (RFC5545) to provide 17 improved status tracking, scheduling and specification of tasks. It 18 also defines how Calendaring Extensions to WebDAV (CalDAV) (RFC 4791) 19 servers can be extended to support certain automated task management 20 behaviours. 22 Status of this Memo 24 This Internet-Draft is submitted in full conformance with the 25 provisions of BCP 78 and BCP 79. 27 Internet-Drafts are working documents of the Internet Engineering 28 Task Force (IETF), its areas, and its working groups. Note that 29 other groups may also distribute working documents as Internet- 30 Drafts. 32 Internet-Drafts are draft documents valid for a maximum of six months 33 and may be updated, replaced, or obsoleted by other documents at any 34 time. It is inappropriate to use Internet-Drafts as reference 35 material or to cite them other than as "work in progress." 37 The list of current Internet-Drafts can be accessed at 38 http://www.ietf.org/ietf/1id-abstracts.txt 40 The list of Internet-Draft Shadow Directories can be accessed at 41 http://www.ietf.org/shadow.html 43 This Internet-Draft will expire on March 17, 2016. 45 Copyright Notice 47 Copyright (c) 2015 IETF Trust and the persons identified as the 48 document authors. All rights reserved. 50 This document is subject to BCP 78 and the IETF Trust's Legal 51 Provisions Relating to IETF Documents 52 (http://trustee.ietf.org/license-info) in effect on the date of 53 publication of this document. Please review these documents 54 carefully, as they describe your rights and restrictions with respect 55 to this document. 57 Table of Contents 59 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 60 1.1. Conventions used in this document . . . . . . . . . . . . . 4 61 1.2. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . 4 62 2. Task Architecture . . . . . . . . . . . . . . . . . . . . . . . 5 63 2.1. Task Architecture Elements . . . . . . . . . . . . . . . . 7 64 2.2. Architecture Foundations . . . . . . . . . . . . . . . . . 8 65 3. Task Extensions . . . . . . . . . . . . . . . . . . . . . . . . 9 66 3.1. Task Specification . . . . . . . . . . . . . . . . . . . . 9 67 3.1.1. STRUCTURED-CATEGORY for task type identification . . . 9 68 3.1.2. Task Context and Relationships . . . . . . . . . . . . 10 69 3.1.3. Task Domain Data Handling . . . . . . . . . . . . . . . 10 70 3.2. Task Deadlines, Milestones and Time Planning . . . . . . . 11 71 3.3. Task Scheduling and Assignment . . . . . . . . . . . . . . 11 72 3.4. Status Reporting . . . . . . . . . . . . . . . . . . . . . 12 73 3.4.1. Improved granularity in status reporting information . 12 74 3.4.2. Relating comments to status . . . . . . . . . . . . . . 12 75 3.4.3. Comments associated to reasons and status changes . . . 12 76 3.4.4. Task Alerts and Notifications . . . . . . . . . . . . . 12 77 3.4.5. Automated Status Changes . . . . . . . . . . . . . . . 13 78 4. New Property Parameters . . . . . . . . . . . . . . . . . . . . 13 79 4.1. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . 13 80 4.2. Modified . . . . . . . . . . . . . . . . . . . . . . . . . 14 81 4.3. Sub-State . . . . . . . . . . . . . . . . . . . . . . . . . 14 82 5. New Parameter Values . . . . . . . . . . . . . . . . . . . . . 15 83 5.1. Redefined VTODO Participant Status . . . . . . . . . . . . 15 84 6. New Properties . . . . . . . . . . . . . . . . . . . . . . . . 15 85 6.1. Estimated Duration . . . . . . . . . . . . . . . . . . . . 15 86 6.2. Task Mode . . . . . . . . . . . . . . . . . . . . . . . . . 16 87 6.2.1 AUTOMATIC-COMPLETION Task Mode . . . . . . . . . . . . . 17 88 6.2.2 AUTOMATIC-FAILURE Task Mode . . . . . . . . . . . . . . 17 89 6.2.3 CLIENT Task Mode . . . . . . . . . . . . . . . . . . . . 18 90 6.2.4 SERVER Task Mode . . . . . . . . . . . . . . . . . . . . 18 91 7. Property Extensions and Clarifications . . . . . . . . . . . . 18 92 7.1. The ATTENDEE property . . . . . . . . . . . . . . . . . . . 18 93 7.2. Redefined COMMENT Property Parameter List . . . . . . . . . 19 94 7.3. Redefined STATUS Property . . . . . . . . . . . . . . . . . 19 95 8. CalDAV Support for Task Mode . . . . . . . . . . . . . . . . . 20 96 8.1. CALDAV:supported-task-mode-set Property . . . . . . . . . . 21 97 9. Security Considerations . . . . . . . . . . . . . . . . . . . . 21 98 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 99 10.1. The Status registry . . . . . . . . . . . . . . . . . . . 21 100 10.1.1 Initialization of the Status registry . . . . . . . . . 21 101 10.1.2 Update of the Status registry . . . . . . . . . . . . . 22 102 10.2. Sub-State value registry . . . . . . . . . . . . . . . . . 22 103 10.3. Task Mode value registry . . . . . . . . . . . . . . . . . 23 104 10.4. Participation Statuses registry . . . . . . . . . . . . . 23 105 10.5. Properties registry . . . . . . . . . . . . . . . . . . . 23 106 10.6. Parameters registry . . . . . . . . . . . . . . . . . . . 24 107 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 24 108 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 25 109 12.1. Normative References . . . . . . . . . . . . . . . . . . . 25 110 12.2. Informative References . . . . . . . . . . . . . . . . . . 25 111 Appendix A. Examples of Task State Lifecycle . . . . . . . . . . . 27 112 A.1. Simple Case Status Change . . . . . . . . . . . . . . . . . 27 113 A.2. Example for multiple Attendees . . . . . . . . . . . . . . 27 114 A.3. Failed Example . . . . . . . . . . . . . . . . . . . . . . 28 115 Appendix B. Working Notes . . . . . . . . . . . . . . . . . . . . 29 116 B.1. Advertising tasks . . . . . . . . . . . . . . . . . . . . . 29 117 B.2. Subscribing to task updates . . . . . . . . . . . . . . . . 29 118 Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . . 30 119 V01. 2015-08-23 AA . . . . . . . . . . . . . . . . . . . . . . . . 30 120 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 31 122 1. Introduction 124 This document specifies extensions to the existing Internet 125 Calendaring and Scheduling Core Object Specification (iCalendar) 126 [RFC5545], and associated protocols, in order to enhance the 127 structured communication and execution of tasks. The enhancements 128 allow for the communication, time planning and scheduling of tasks by 129 and between automated systems (e.g. in smart power grids, business 130 process management systems) as well as for human centered tasks. 132 A "task" is a representation of an item of work assigned to an 133 individual or organization. In the iCalendar Object Model [RFC5545] 134 the representation of tasks is by "VTODO" calendar components. Tasks 135 can be identified in a number of situations, either informally as 136 ad-hoc tasks in personal "to-do" lists or more formally in: 138 o Business processes - ranging from repetitive workflows to adaptive 139 cases and trouble ticketing 141 o Project Management - whether for large scale construction projects 142 or collaborative software development 144 The extensions specified here are defined in the context of an 145 overall architecture for task calendaring and scheduling. 147 1.1. Conventions used in this document 149 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 150 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 151 document are to be interpreted as described in RFC-2119 [RFC2119]. 153 1.2. Glossary 155 The following calendaring and scheduling terms are applied throughout 156 this document: 158 o Assignee - A calendar user assigned to perform a given task. An 159 assignee is equivalent to an attendee of an event. 161 o Calendar User (CU) - A person or software system that accesses or 162 modifies calendar information. 164 o Calendar User Agent (CUA) - (1) Software with which the calendar 165 user communicates with a calendar service or local calendar store 166 to access calendar information. (2) Software that gathers 167 calendar data on the Calendar User's behalf. 169 o Candidate - A calendar user who might be able to perform a given 170 task, prior to actually being assigned the task, e.g., a 171 dispatcher has a list of taxi drivers (candidates) from which one 172 will be selected to pick-up a passenger. 174 o Organizer - A calendar user who creates a calendar item, requests 175 free/busy information, or published free/busy information. It is 176 an Organizer who invites Attendees [RFC5545]. 178 o Observer - A calendar user interested in a calendar component, 179 e.g., a manager may have interest in all tasks that have not been 180 completed. 182 o Resource - A resource in the scheduling context is any shared 183 entity that can be scheduled by a calendar user, but does not 184 control its own attendance status. Resources can be of "Location", 185 "Equipment", or "Role" type. 187 o Task - A representation of an item of work that can be assigned to 188 one or more task actor assignees. In [RFC5545], these are "VTODO" 189 calendar components, which are groupings of component properties 190 and possibly "VALARM" calendar components that represent an 191 action-item or assignment. 193 2. Task Architecture 195 A reference architecture for task calendaring and scheduling is 196 defined in order to identify the key logical elements involved in 197 task management and the interfaces between them to enable 198 interoperability. The logical elements identified here establish an 199 appropriate separation of concerns and clarify the responsibilities 200 of different elements. However, the architecture does not prescribe a 201 binding or packaging of elements, i.e., software systems may be 202 developed where some elements are tightly bound and the interfaces 203 between bound elements are not exposed. The task architecture is also 204 described in [TARCH]. 206 Task +-------+ 207 Trigger | 208 +---------------------V---------------------+ +-----------+ 209 | Task Generating System | | | 210 | +-------------------------+ | | | 211 | | O | | | | 212 | | /|\ | | | | 213 | | / \ | | | | 214 | | Task Organizer | <----> | 215 | +-^--------^--------------+ | | | 216 | | | | | | 217 | +--------V-+ +----V-----+ +----------+ | | | 218 | | Task | | Process | | Task | | | | 219 | |Assignment| | Logic <----> Domain | | | | 220 | | Rules | | | | Data | | | | 221 | +----------+ +----------+ +----------+ | | | 222 | | | | 223 +------^----------+-----^-------------------+ | | 224 | | | | | 225 Availability Task Task | | 226 | | Status | | 227 | | | | | 228 +------v----------v-----+-------------------+ | | 229 | Calendar and Scheduling System | | Directory | 230 | +---------+ +---------+ | | Service | 231 | | | | Task | <----> | 232 | |Schedule | | Lists | | | | 233 | | | | | | | | 234 | +---------+ +---------+ Server | | | 235 +-------------------------------------------+ | | 236 | Client | | | 237 | +----------------------+ +-----------+ | | | 238 | | Calendar | | Task | | | | 239 | | User Agent +----> Specific | <----> | 240 | | | |Application| | | | 241 | +----------------------+ +-----------+ | | | 242 | | | | 243 +-----^---------^--------+---------+--------+ | | 244 | | | | | | 245 +-----V---------V--------V---------V--------+ | | 246 | Task Actors | | | 247 | O O O O | | | 248 | /|\ /|\ /|\ /|\ +----> | 249 | / \ / \ / \ / \ | | | 250 | Candidate(s) Observer(s) | | | 251 | Assignee(s) Resource(s) | | | 252 +-------------------------------------------+ +-----------+ 254 2.1. Task Architecture Elements 256 The following logical elements form the task architecture that this 257 specification is based on: 259 o Task Actors - Various calendar users that may be involved in the 260 monitoring or performing of a task. The set of actors includes: 261 Organizers, Observers, Resources, Assignees, and Candidates. 263 o Task Organizer - The Organizer of a task. 265 o Task Domain Data - This is any domain specific data that may be 266 acted on or provides context to it in performing a task. 268 o Task Specific Application - A task specific application renders 269 the data concerning the task (including task domain data) for 270 presentation and manipulation by a task actor. 272 o Process Logic - Process logic determines under what conditions a 273 task (or tasks) is generated and the actions to take on 274 completion, or some other status event occurring (or not) on the 275 task. 277 o Task Trigger - This is some event that gives rise to the 278 generation of a task according to Process Logic. Task triggers can 279 come from many different sources including, for example; a task 280 being requested through the calendaring system, a status change in 281 the progression of a business process being managed by a business 282 process management or ERP system. 284 o Task Assignment Rules - Rules that govern how actors are assigned 285 to a task. A range of different assignment patterns [WfRP] may be 286 considered, including the two general cases: 288 1. Delegation to a named actor or group of actors 290 2. Advertising to a pool of actors for self-selection 292 In either case the assignment may be made based on a variety of 293 criteria including, name, availability, skills, capacity, etc. 295 o Task Generating System - A system that creates and assigns tasks 296 in response to some initiating event (task trigger). Task creation 297 is according to Process Logic with task assignment determined by 298 Task Assignment Rules. This system also tracks the status of tasks 299 and will initiate further actions based upon the status. A task 300 generating system can take many forms, for example; Business 301 Process Management System, Project Management System, Bug Tracking 302 System, Building Control System. A Task Generating System may also 303 be a human. In iCalendar terms the Task Generating System is the 304 organizer. 306 o Human Task Generation - Task creation, assignment and tracking 307 coordinated by a human organizer is a special case of a task 308 generating system. In this case Task Assignment Rules and Process 309 Logic may be either explicit or tacit. 311 o Directory Service - A software system that stores and provides 312 access to information providing details of task actors that may 313 participate or be interested in a task. 315 o Calendar and Scheduling System - A software system that stores, 316 publishes and synchronizes calendar data such as events, tasks and 317 journal entries for actors. In the context of tasks this includes 318 schedules (i.e. allocated time and availability to perform tasks) 319 and task lists. A calendar and scheduling system typically 320 consists of server and client software components. 322 It is not within the scope of this document to specify how Process 323 Logic or Task Assignment Rules are codified. Such logic and rules may 324 be codified in a variety of ways, including traditional programming 325 languages (e.g. C++, Java) or process modelling languages (e.g. BPMN 326 [BPMN]). 328 2.2. Architecture Foundations 330 The key standards that enable interoperability between the logical 331 elements of the architecture are the Internet Calendaring and 332 Scheduling Core Object Specification (iCalendar) [RFC5545] and 333 associated protocols. Task and task status are represented by the 334 iCalendar "VTODO" component. Protocols include, in particular, the 335 iCalendar Transport-Independent Interoperability Protocol (iTIP) 336 [RFC5546] for task assignment and scheduling, and Calendaring 337 Extensions to WebDAV (CalDAV) [RFC 4791] for client server 338 communication. 340 Additionally, other iCalendar extensions embraced by this 341 specification include: 343 o Support for iCalendar Relationships [Doug114] - The LINK, REFID, 344 RELATED-TO and STRUCTURED-CATEGORY properties enable context and a 345 rich set of relationships between tasks and other iCalendar 346 components to be specified. 348 o Event Publishing Extensions to iCalendar [Doug214] - The GROUP 349 parameter specifically enables the grouping of properties 350 associated with specific status changes of a task. 352 3. Task Extensions 354 In order to support the task architecture described in section 3, 355 this document defines a number of extensions to the current iCalendar 356 standards in the areas of: 358 o Task Specification - improved ability to specify domain specific 359 tasks 361 o Task Deadlines, Milestones and Time Planning - clarification of 362 deadlines and extension for task duration to support task time 363 planning 365 o Task Scheduling and Assignment - ensure support for common pattens 366 of scheduling and assigning tasks 368 o Task Status Tracking - improved granularity in status tracking 369 information and alerting task actors to pending or actual task 370 status changes 372 These extensions are supported mainly by additions to the properties 373 and parameters used within the "VTODO" component. 375 3.1. Task Specification 377 The specification of tasks must be semantically explicit in order for 378 them to be managed within the context of a business process or 379 project, and be understood by both humans and IT systems. The current 380 VTODO component only provides for simple ad-hoc tasks or 'to do' 381 lists, and is therefore extended by this specification as follows: 383 o Task type - explicitly what type of task is to be performed is 384 identified. 386 o Task context and relationships - how a specific task relates to 387 other tasks and other objects that need to be understood for the 388 effective execution of a task. 390 o Task specific data - the form and content of domain data provided 391 as input to a task and/or that may be output from a task. 393 o Organizer and attendee - recognizes that a task organizer or 394 attendee can be an automated system. 396 3.1.1. STRUCTURED-CATEGORY for task type identification 397 The STRUCTURED-CATEGORY property is used to identify the type of 398 task, for example; 400 STRUCTURED-CATEGORY:http://example.com/task/delivery 402 3.1.2. Task Context and Relationships 404 The LINK property specifies a link to external information, which may 405 be context to the task. For example: 407 LINK;REL=SOURCE:http://example.com/package/1234567890 409 LINK;REL=describedby:mid:752142.1414823874.307E5@mx123.example.com 411 The external information may be data to be manipulated in performing 412 the task. See section 3.1.3 Task Domain Data Handling. 414 REFID is used to identify a key allowing the association of tasks 415 that are related to the same object and retrieval of a task based on 416 this key. This may be, for example, to identify the tasks associated 417 with a given project without having to communicate the task structure 418 of the project, or all tasks associated to a specific package. 420 REFID:Manhattan 422 REFID:1234567890 424 Extensions [Doug114] to the RELATED-TO property allow temporal 425 relationships between tasks as found in project management to be 426 specified as well as parent / child relationships and dependencies 427 (DEPENDS-ON). Tasks (VTODOs) may also be related to other calendar 428 components; for example to a VEVENT to block time to perform a task. 430 3.1.3. Task Domain Data Handling 432 Provide support for task specific input and output data (including 433 updates) beyond the standard iCalendar properties. It is envisaged 434 that standard calendar user agents will be able to launch task 435 specific applications by passing task specific data. 437 The LINK property can be used to 'attach' the domain specific data to 438 the task. For example, it might be a URI pointing to a web page where 439 the status of the task can be directly manipulated. 441 LINK;REL="vacation-system";VALUE=URI:http://example.com/ 442 vacation-approval?id=1234 444 Or it might be used for attachments specific to the task, for example 445 an electronic copy of a signature taken to confirm delivery of a 446 package. 448 LINK;REL="electronic-signature";VALUE=URI:http://example.com/ 449 delivery/sig1234.jpg 451 3.2. Task Deadlines, Milestones and Time Planning 453 Deadlines for starting and finishing a task are defined by the 454 DTSTART, DUE and DURATION properties. DTSTART represents the earliest 455 start time for beginning work on a task. DUE, or DTSTART + DURATION 456 represent the latest finish time for a task. Thus these properties 457 define a "window" within which a task has to be performed. However, 458 there is currently no way to indicate how long the task is expected 459 to take. This document defines a new property, ESTIMATED-DURATION, to 460 allow the estimated time that a task should take to be specified 461 separately from the deadlines for starting and finishing a task. This 462 supports time planning by enabling calendar user agents to display 463 when tasks should occur and therefore allow calendar users to 464 visualize when tasks should be performed and allocate time to them. 466 A task that has intermediary deadlines (i.e., milestones) SHOULD be 467 expressed by child VTODO components (i.e., sub-tasks associated with 468 each of the milestones) in conjunction with the RELATED-TO property 469 to relate the parent and child tasks. 471 3.3. Task Scheduling and Assignment 473 This specification supports the two distinct models of assigning 474 actors to tasks, i.e., 1) strictly one assignee per task or 2) task 475 assignment to multiple assignees. In this regard one or many 476 ATTENDEES may be specified against a task depending upon the model 477 applied by the task organizer. 479 In addition a number of different patterns of resource or assignee 480 identification are anticipated. The specific Task Assignment Rules 481 are the responsibility of the Task Organizer. 483 Communication of task assignment or delegation to one or more actors 484 who are allocated to a task by the organizer is directly supported by 485 iTIP, i.e., all included ATTENDEES in an iTIP REQUEST are expected to 486 perform the task. 488 The offering or advertising of a task to one or more (potential) 489 actors where only one or a subset of the candidates may accept the 490 task will be addressed by a new VPOLL mode (See Appendix B) [VPOLL]. 492 3.4. Status Reporting 494 3.4.1. Improved granularity in status reporting information 496 This document defines new status parameters that can be applied to 497 the VTODO status (STATUS) property, as well as the participant status 498 (PARTSTAT) parameter. These new parameters provide additional 499 information on why (REASON) and when (MODIFIED) a status has changed. 500 In addition to these parameters new status values are specified to 501 provide for task suspension, failure and preparation. 503 3.4.2. Relating comments to status 505 The GROUP parameter is used with the STATUS or ATTENDEE properties to 506 relate an associated COMMENT property. The COMMENT property can then 507 be used to include additional human readable information about why 508 the associated STATUS or ATTENDEE property changed. 510 STATUS;REASON="http://example.com/reason/delivery-failed";SUBSTATE 511 =ERROR;MODIFIED=20130212T120000Z;GROUP=G1:FAILED 512 COMMENT;MODIFIED=20130226T110451Z;GROUP=G1:Breakdown 514 ATTENDEE;PARTSTAT=FAILED;MODIFIED=20130226T1104510Z;GROUP=G2: 515 REASON="http://example.com/reason/van-break-down":mailto: 516 xxx@example.com 517 COMMENT;MODIFIED=20130226T110451Z;GROUP=G2:Puncture 519 3.4.3. Comments associated to reasons and status changes 521 Reasons may be associated directly with a comment, allowing for 522 multiple reasons associated with a status to each have a comment 523 associated with them [EDISTS]. 525 STRUCTURED-CATEGORY:http://example.com/task/delivery 526 STATUS;SUBSTATE=ERROR;MODIFIED=20130212T120000Z;GROUP=G1:FAILED 527 COMMENT;MODIFIED=20130226T110451Z;GROUP=G1:Out of time 529 COMMENT;REASON="http://example.com/reason/traffic";MODIFIED= 530 20130226T110451Z;GROUP=G1:Traffic Accident on E44 532 COMMENT;REASON="http://example.com/reason/closed";MODIFIED= 533 20130226T110451Z;GROUP=G1:Arrived after office hours 535 3.4.4. Task Alerts and Notifications 537 Different needs to alert or notify task actors of pending or actual 538 task status changes are recognized: 540 o Alarms - Alarms (VLARM components) operate in the calendar user 541 agent space to notify the task actor of a pending task state for a 542 task they are assigned to or are interested in. Note: there is no 543 constraint in the current standards on the propagation of alarms 544 specified on calendar objects by organizers to individual 545 attendees. 547 o Escalations - An escalation or notification to the ATTENDEE, 548 ORGANIZER, or other task actor may be required if a deadline 549 associated with a task is exceeded or for some other reason. 550 Process Logic identifying when and who to propagate escalations to 551 is the responsibility of the Task Generating System, e.g., a BPMS. 553 o Notifications - Task actors (observers) not directly involved in 554 performing a task but with a known interest in a given task's 555 status can be identified by the ASSOCIATE property [Doug214] 556 against certain components e.g. ALARM, to identify which task 557 events the stakeholder / party is interested in. Notifications on 558 shared calendars will allow task actors to register an interest in 559 changes to tasks within a calendar (see Appendix B.2). 561 3.4.5. Automated Status Changes 563 A new property, TASK-MODE, is introduced to instruct servers to apply 564 automated operations for changing the status of a task. 566 4. New Property Parameters 568 4.1. Reason 570 Parameter name: REASON 572 Purpose: To indicate the reason for a change in status of a task or 573 attendee participation status. 575 Format Definition: This parameter is defined by the following 576 notation: 578 reasonparam = "REASON" "=" DQUOTE uri DQUOTE 579 *("," DQUOTE uri DQUOTE) 581 Description: This property parameter allows the change in status of 582 a task or participant status to be qualified by the reason for the 583 change with a codified reason. Typically reasons are defined within 584 the context of the task type and therefore SHOULD include the name- 585 space of the authority defining the task. Common reason codes are 586 IANA registered and do not have a name-space prefix. 588 Example: 590 STATUS;REASON="http://example.com/reason/delivered-on-time"; 591 MODIFIED=20130212T120000Z;GROUP=G1:COMPLETED 593 ATTENDEE;REASON="x-example-reason:out-of-office";PARTSTAT= 594 DECLINED;MODIFIED=20130212T120000Z;GROUP=123:mailto: 595 cyrus@example.com 597 4.2. Modified 599 Parameter name: MODIFIED 601 Purpose: To specify the time and date of when the status of a task 602 or attendee participant status changed. 604 Format Definition: This parameter is defined by the following 605 notation: 607 modifiedparam = "MODIFIED" "=" date-time 609 Description: The modified parameter allows the specification of the 610 date time of when a status (STATUS) or participant status (PARTSTAT) 611 changed. It MUST be specified in the UTC time format. The value of 612 MODIFIED SHOULD be set at the time when the associated status (either 613 STATUS or PARTSTAT)is changed. Therefore either a client or server 614 may set the value of MODIFIED depending on which is updating the 615 value of STATUS or PARTSTAT. For backwards compatibility if the 616 server detects that MODIFIED should have changed but wasn't (for 617 example the client doesn't support MODIFIED) then the server MAY set 618 MODIFIED retrospectively. 620 Example: 622 STATUS;REASON=""http://example.com/reason/delivered-on-time"; 623 MODIFIED=20130212T120000Z;GROUP=G1:COMPLETED 625 4.3. Sub-State 627 Parameter name: SUBSTATE 629 Purpose: To provide additional granularity of task status for e.g. 630 IN-PROCESS. 632 Format Definition: This parameter is defined by the following 633 notation: 635 substateparam = "SUBSTATE" "=" 636 ( "OK" ; everything is fine(the default) 637 / "ERROR" ; something is wrong (the REASON 638 ; code explains why) 639 / "SUSPENDED" ; waiting on some other task to 640 ; complete or availability of a 641 ; resource (REASON code explains 642 ; why) 643 / x-name ; Experimental type 644 / iana-token) ; Other IANA-registered type 646 Description: The sub-state parameter allows additional qualification 647 and granularity of states to be recorded, in particular for the IN- 648 PROCESS state. It allows individual sub-states to be recorded without 649 the need to define and publish a sub-task associated with a parent 650 task purely to track that a particular state has been reached. This 651 property also allows parallel states to be expressed e.g. that a task 652 has been suspended at whatever state it has reached. 654 Example: 656 STATUS;REASON="http://example.com/reason/no-one-home";SUBSTATE= 657 ERROR:FAILED 658 STATUS;REASON="http://example.com/reason/paint-drying";SUBSTATE= 659 SUSPENDED:IN-PROCESS 661 5. New Parameter Values 663 5.1. Redefined VTODO Participant Status 665 Participant status parameter type values are defined in section 666 3.2.12. of [RFC5545]. This specification redefines that type to 667 include the new value FAILED for VTODO iCalendar components. 669 Format Definition: This property parameter is extended by the 670 following notation: 672 partstat-todo /= *("FAILED") ; To-do cannot be completed 674 Example: 676 ATTENDEE;REASON="http://example.com/reason/not-enough-time"; 677 PARTSTAT=FAILED:mailto:jsmith@example.com 679 6. New Properties 681 6.1. Estimated Duration 683 Property Name: ESTIMATED-DURATION 684 Purpose: This property specifies the estimated positive duration of 685 time the corresponding task will take to complete. 687 Value Type: DURATION 689 Property Parameters: IANA and non-standard property parameters can 690 be specified on this property. 692 Conformance: This property can be specified in "VTODO" calendar 693 components. 695 Format Definition: This property is defined by the following 696 notation: 698 est-duration = "ESTIMATED-DURATION" durparam ":" dur-value CRLF 699 ;consisting of a positive duration of time. 701 durparam = *(";" other-param) 703 Description: In a "VTODO" calendar component the property MAY be 704 used to specify the estimated duration for the to-do, with or without 705 an explicit time window in which the event should be started and 706 completed. When present, DTSTART and DUE/DURATION represent the 707 window in which the task can be performed. ESTIMATED-DURATION SHOULD 708 be passed from ORGANIZER to ATTENDEE in iTIP [RFC5546] messages. 710 Example: The following is an example of this property that specifies 711 an interval of time of exactly one hour: 713 ESTIMATED-DURATION:PT1H 715 6.2. Task Mode 717 Property Name: TASK-MODE 719 Purpose: This property specifies automatic operations that servers 720 apply to tasks based on changes in attendee status (PARTSTAT). 722 Value Type: TEXT 724 Property Parameters: IANA and non-standard property parameters can 725 be specified on this property. 727 Conformance: This property can be specified zero or more times in a 728 "VTODO" calendar component. 730 Format Definition: This property is defined by the following 731 notation: 733 task-mode = "TASK-MODE taskmodeparam ":" taskvalue 734 *("," taskvalue) CRLF 736 taskvalue = "AUTOMATIC-COMPLETION" ; set STATUS completed 737 ;if all attendees have completed 738 / "AUTOMATIC-FAILURE" 739 / "SERVER" 740 / "CLIENT" 741 / iana-token 742 / x-name 744 taskmodeparam = *(";" other-param) 746 Description: In a "VTODO" calendar component this property MAY be 747 used to indicate to servers how they can automatically change the 748 state of the task based on iTIP replies from Attendees. For example, 749 the server can automatically set the overall task status (STATUS) to 750 COMPLETED when every attendee has marked their own status (PARTSTAT) 751 as COMPLETED, or the server could mark the task as FAILED if its DUE 752 date passes without it being completed. TASK-MODE processing is 753 performed on the organizer's copy of the task. 755 The property value is a list of one or more IANA registered tokens 756 that defines modes to be used for the task. This specification 757 defines three modes which are described in the following sub- 758 sections. 760 Examples: 762 TASK-MODE:AUTOMATIC-COMPLETION,AUTOMATIC-FAILURE 763 TASK-MODE:SERVER 764 TASK-MODE:AUTOMATIC-FAILURE 766 6.2.1 AUTOMATIC-COMPLETION Task Mode 768 The task mode value "AUTOMATIC-COMPLETION" indicates to the server 769 that it can change the "VTODO" component's STATUS property value to 770 "COMPLETED" as soon as all ATTENDEEs in the task have replied with a 771 "PARTSTAT" parameter set to "COMPLETED". 773 6.2.2 AUTOMATIC-FAILURE Task Mode 775 The task mode value "AUTOMATIC-FAILURE" indicates to the server that 776 it SHOULD change the "VTODO" component's STATUS property value to 777 "FAILED" if either: 779 o the PARTSTAT of one ATTENDEE is set to FAILED; or 780 o the current time is past the effective due date of the component 781 and the task has not yet been completed. 783 Note: The effective due date is either the "DUE" property value or 784 the combination of the "DTSTART" and "DURATION" property values. 786 6.2.3 CLIENT Task Mode 788 The task mode value "CLIENT" is an instruction to the server to 789 honour the status set by the client. 791 6.2.4 SERVER Task Mode 793 The task mode value "SERVER" indicates to the server that it can 794 change the "VTODO" component's STATUS property value to an 795 appropriate value, based on implementation defined "business rules", 796 as ATTENDEE responses are processed or as deadlines related to the 797 task pass. 799 The server can add this property to a "VTODO" component to indicate 800 to the client that it will be managing the status. 802 7. Property Extensions and Clarifications 804 7.1. The ATTENDEE property 806 The Attendee property is defined in section 3.8.4.1. of [RFC5545]. 807 This specification extends that property to include new parameters to 808 indicate the reason for a participant status change (See Appendix A) 809 and sub-states. 811 Format Definition: This property is defined by the following 812 notation: 814 attendee = "ATTENDEE" attparam ":" cal-address CRLF 816 attparam /= *( 817 ; 818 ; The following are OPTIONAL, 819 ; but MUST NOT occur more than once. 820 ; 821 (";" reasonparam) 822 (";" modifiedparam) 823 (";" substateparam) 824 ) 826 Example: The following are examples of this property's use for tasks: 828 ATTENDEE;PARTSTAT=DECLINED;MODIFIED=20130212T120000Z;GROUP=G1; 829 REASON="http://example.com/reason/too-busy": 830 mailto:xxx@example.com 832 ATTENDEE;PARTSTAT=IN-PROCESS;MODIFIED=20130212T120000Z; 833 SUBSTATE=X-EXAMPLE-STEP-1:mailto:xxx@example.com 835 7.2. Redefined COMMENT Property Parameter List 837 The Comment property is defined in section 3.8.1.4. of [RFC5545]. 839 Format Definition: The "COMMENT" property parameter list is 840 augmented as follows: 842 commparam /= *( 843 ; The following are OPTIONAL, 844 ; but MUST NOT occur more than once. 845 (";" reasonparam) / 846 (";" modifiedparam) 847 ) 849 7.3. Redefined STATUS Property 851 The Status property is defined in section 3.8.1.11. of [RFC5545]. 852 This specification extends that property to include new parameters to 853 indicate the reason for a status change as well as new values 854 associated with VTODO iCalendar components (See Appendix A for 855 examples of the task state lifecycle). 857 Format Definition: The "STATUS" property parameter list is augmented 858 as follows: 860 statparam /= *( 861 ; The following are OPTIONAL, 862 ; but MUST NOT occur more than once. 863 ; 864 (";" reasonparam) 865 (";" modifiedparam) 866 (";" substateparam) / 867 ) 869 statvalue-todo = / "PENDING" ;Indicates a to-do has been 870 ;created and accepted, but has not 871 ;yet started. 872 / "FAILED" ;Indicates to-do has failed. 873 ;Extended status values for 874 ;"VTODO". 876 Description: 878 PENDING - A task has been created but has not yet started and is 879 ready to start subject to other dependencies (e.g. preceding task or 880 DTSTART). This is the default state. 882 FAILED - task has failed and may need some follow-up from the 883 organizer to re-schedule or cancel 885 Example: The following is an example of this property for a "VTODO" 886 calendar component: 888 STATUS;REASON="http://example.com/reason/delivery-failed";SUBSTATE 889 =ERROR;MODIFIED=20130212T120000Z;GROUP=G1:FAILED 891 8. CalDAV Support for Task Mode 893 The CalDAV [RFC4791] calendar access protocol allows clients and 894 servers to exchange iCalendar data. With the introduction of the 895 "TASK-MODE" property in this specification, different automated task 896 management behaviours may be delegated to the server by the Task 897 Organizer depending upon the value of "TASK-MODE". 899 In order for a CalDAV client to know what task modes are available, a 900 CalDAV server advertises a CALDAV:supported-task-mode-set WebDAV 901 property on calendar home or calendar collections if it supports the 902 use of the "TASK-MODE" property as described in this specification. 903 The server can advertise a specific set of supported task modes by 904 including one or more CALDAV:supported-task-mode XML elements within 905 the CALDAV:supported-task-mode-set XML element. If no 906 CALDAV:supported-task-mode XML elements are included in the WebDAV 907 property, then clients can try any task mode, but need to be prepared 908 for a failure when attempting to store the calendar data. 910 Clients MUST NOT attempt to store iCalendar data containing "TASK- 911 MODE" elements if the CALDAV:supported-task-mode-set WebDAV property 912 is not advertised by the server. 914 The server SHOULD return an HTTP 403 response with a DAV:error 915 element containing a CALDAV:supported-task-mode XML element, if a 916 client attempts to store iCalendar data with an "TASK-MODE" element 917 value not supported by the server. 919 It is possible for a "TASK-MODE" value to be present in calendar data 920 on the server being accessed by a client that does not support the 921 "TASK-MODE" property. It is expected that existing clients, unaware 922 of "TASK-MODE", will fail gracefully by ignoring the calendar 923 property. 925 8.1. CALDAV:supported-task-mode-set Property 927 Name: supported-task-mode-set 929 Namespace: urn:ietf:params:xml:ns:caldav 931 Purpose: Enumerates the set of supported iCalendar "TASK-MODE" 932 element values supported by the server. 934 Protected: This property MUST be protected and SHOULD NOT be 935 returned by a PROPFIND allprop request (as defined in Section 14.2 of 936 [RFC4918]). 938 Description: See above. 940 Definition: 942 943 944 947 Example: 949 951 AUTOMATIC-COMPLETION 952 AUTOMATIC-FAILURE 953 SERVER 954 CLIENT 955 957 9. Security Considerations 959 This specification introduces no new security considerations beyond 960 those identified in RFC 5545. 962 10. IANA Considerations 964 10.1. The Status registry 966 10.1.1 Initialization of the Status registry 968 This specification updates [RFC5545] by adding a Status value 969 registry to the iCalendar Elements registry and initializing it as 970 per [RFC5545]. 972 +--------------+---------+------------------------------+ 973 | Status | Status | Reference | 974 +--------------+---------+------------------------------+ 975 | CANCELLED | Current | [RFC5545], Section 3.8.1.11. | 976 | | | | 977 | COMPLETED | Current | [RFC5545], Section 3.8.1.11. | 978 | | | | 979 | CONFIRMED | Current | [RFC5545], Section 3.8.1.11. | 980 | | | | 981 | DRAFT | Current | [RFC5545], Section 3.8.1.11. | 982 | | | | 983 | FINAL | Current | [RFC5545], Section 3.8.1.11. | 984 | | | | 985 | IN-PROCESS | Current | [RFC5545], Section 3.8.1.11. | 986 | | | | 987 | NEEDS-ACTION | Current | [RFC5545], Section 3.8.1.11. | 988 | | | | 989 | TENTATIVE | Current | [RFC5545], Section 3.8.1.11. | 990 +--------------+---------+------------------------------+ 992 10.1.2 Update of the Status registry 994 This specification further updates the Status registry with 995 additional values defined in this document. 997 +-----------+---------+-------------------------+ 998 | Status | Status | Reference | 999 +-----------+---------+-------------------------+ 1000 | PENDING | Current | This Spec, Section 7.3. | 1001 | | | | 1002 | FAILED | Current | This Spec, Section 7.3. | 1003 +-----------+---------+-------------------------+ 1005 10.2. Sub-State value registry 1007 The following table has been used to initialize the Sub-State 1008 registry. 1010 +-----------+---------+-------------------------+ 1011 | Substate | Status | Reference | 1012 +-----------+---------+-------------------------+ 1013 | OK | Current | This Spec, Section 4.3. | 1014 | | | | 1015 | ERROR | Current | This Spec, Section 4.3. | 1016 | | | | 1017 | SUSPENDED | Current | This Spec, Section 4.3. | 1018 +-----------+---------+-------------------------+ 1020 10.3. Task Mode value registry 1022 The following table has been used to initialize the Task Mode 1023 registry. 1025 +----------------------+---------+-------------------------+ 1026 | Task Mode | Status | Reference | 1027 +----------------------+---------+-------------------------+ 1028 | AUTOMATIC-COMPLETION | Current | This Spec, Section 6.2. | 1029 | | | | 1030 | AUTOMATIC-FAILURE | Current | This Spec, Section 6.2. | 1031 | | | | 1032 | CLIENT | Current | This Spec, Section 6.2. | 1033 | | | | 1034 | SERVER | Current | This Spec, Section 6.2. | 1035 +----------------------+---------+-------------------------+ 1037 10.4. Participation Statuses registry 1039 The following table has been used to update the Participation 1040 Statuses registry. 1042 +-----------+---------+-------------------------+ 1043 | Status | Status | Reference | 1044 +-----------+---------+-------------------------+ 1045 | FAILED | Current | This Spec, Section 5.1. | 1046 +-----------+---------+-------------------------+ 1048 10.5. Properties registry 1050 The following table has been used to update the Properties registry. 1052 +--------------------+---------+-------------------------+ 1053 | Property | Status | Reference | 1054 +--------------------+---------+-------------------------+ 1055 | ATTENDEE | Current | This Spec, Section 7.1. | 1056 | | | | 1057 | COMMENT | Current | This Spec, Section 7.2. | 1058 | | | | 1059 | ESTIMATED_DURATION | Current | This Spec, Section 6.1. | 1060 | | | | 1061 | STATUS | Current | This Spec, Section 7.3. | 1062 | | | | 1063 | TASK-MODE | Current | This Spec, Section 6.2. | 1064 +--------------------+---------+-------------------------+ 1066 10.6. Parameters registry 1068 The following table has been used to update the Parameters registry. 1070 +-----------+---------+-------------------------+ 1071 | Parameter | Status | Reference | 1072 +-----------+---------+-------------------------+ 1073 | REASON | Current | This Spec, Section 4.1. | 1074 | | | | 1075 | MODIFIED | Current | This Spec, Section 4.2. | 1076 | | | | 1077 | SUBSTATE | Current | This Spec, Section 4.3. | 1078 +-----------+---------+-------------------------+ 1080 11. Acknowledgements 1082 The authors would like to thank the members of the Calendaring and 1083 Scheduling Consortium technical committees and the following 1084 individuals for contributing their ideas, support and comments: 1086 John Chaffee, Marten Gajda, Ken Murchison 1088 The authors would also like to thank the Calendaring and Scheduling 1089 Consortium for advice with this specification. 1091 This document was prepared using Internet-Draft Nroff Editor. 1093 12. References 1095 12.1. Normative References 1097 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1098 Requirement Levels", BCP 14, RFC 2119, March 1997. 1100 [RFC2234] Crocker, D. and Overell, P.(Editors), "Augmented BNF for 1101 Syntax Specifications: ABNF", RFC 2234, Internet Mail 1102 Consortium and Demon Internet Ltd., November 1997. 1104 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 1105 January 2004. 1107 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 1108 Resource Identifier (URI): Generic Syntax", STD 66, RFC 1109 3986, January 2005. 1111 [RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault,"Calendaring 1112 Extensions to WebDAV (CalDAV)", RFC 4791, March 2007. 1114 [RFC4918] Dusseault, L., "HTTP Extensions for Web Distributed 1115 Authoring and Versioning (WebDAV)", RFC 4918, June 2007. 1117 [RFC5545] Desruisseaux, B., "Internet Calendaring and Scheduling Core 1118 Object Specification (iCalendar)", RFC 5545, September 1119 2009. 1121 [RFC5546] Daboo, C., "iCalendar Transport-Independent 1122 Interoperability Protocol(iTIP)", RFC 5546, December 2009. 1124 [Doug114] Douglass, M., "Support for Icalendar Relationships", draft- 1125 douglass-ical-relations-04, January 14, 2015 1127 [Doug214] Douglass, M., "Event Publishing Extensions to iCalendar", 1128 draft-douglass-calendar-extension-04, February 1, 2014 1130 12.2. Informative References 1132 [BPMN] Object Management Group, Business Process Model and 1133 Notation, Version 2.0.2, December 2013, 1134 http://www.omg.org/spec/BPMN/ 1136 [EDISTS] UN Economic Commission for Europe, UN/EDIFACT, D14.A, STS 1137 STATUS, April 30, 2014, http://www.unece.org/fileadmin/ 1138 DAM/trade/untdid/d14a/trsd/trsdsts.htm 1140 [TARCH] Apthorp, A., Daboo, C., Douglass, M., CalConnect, Task 1141 Architecture V1.0, 1144 [VPOLL] York, E., Daboo, C., Douglass, M., "VPOLL: Consensus 1145 Scheduling Component for iCalendar", draft-york-vpoll-03, 1146 January 6, 2015, https://tools.ietf.org/html/draft-york- 1147 vpoll-03 1149 [WfRP] Russell, N., ter Hofstede, A.H.M., Edmond, T., van der 1150 Aalst,W.M.P., Workflow Resource Patterns, Eindhoven 1151 University of Technology, 2004, 1152 1154 [WSCal] Considine, T., Douglass, M., WS-Calendar Version 1.0, 1155 OASIS, 30 July 2011, 1159 [WSHT] Ings, D., Clement, L., Koenig, D., Mehta, V., Mueller, R., 1160 Rangaswamy, R., Rowley, M., Trickovic, I., Web Services - 1161 Human Task Version 1.1 (WS-HumanTask), OASIS, 17 August 1162 2010, 1165 Appendix A. Examples of Task State Lifecycle 1167 A.1. Simple Case Status Change 1169 Example of status changes in assigning and performing a task with one 1170 attendee. 1172 STATUS PARTSTAT Action 1173 ------ -------- ------ 1174 1. - - Organizer draft 1175 2. NEEDS-ACTION NEEDS-ACTION Organizer sends iTIP request 1176 3. NEEDS-ACTION ACCEPTED Attendee reply 1177 4. PENDING ACCEPTED Task accepted but waiting on some 1178 "trigger" to start (e.g. another 1179 task has to finish first) 1180 5. IN-PROCESS IN-PROCESS Attendee reply now working on the 1181 task 1182 6. IN-PROCESS COMPLETED Attendee reply completed 1183 7. COMPLETED COMPLETED Organizer changes overall state 1185 A.2. Example for multiple Attendees 1187 Example of status changes in assigning and performing a task with two 1188 attendees (A1 and A2). 1190 STATUS PARTSTAT (A1) PARTSTAT (A2) Action 1191 ------ ------------ ------------ ------ 1192 1. - - - Organizer draft. 1193 2. NEEDS-ACTION NEEDS-ACTION NEEDS-ACTION Organizer sends 1194 iTIP request. 1195 3. NEEDS-ACTION ACCEPTED NEEDS-ACTION Attendee 1 reply. 1196 3. NEEDS-ACTION ACCEPTED ACCEPTED Attendee 2 reply. 1197 4. PENDING ACCEPTED ACCEPTED Task accepted but 1198 waiting on some 1199 "trigger" to start 1200 (e.g. another task 1201 has to finish 1202 first) 1203 5. IN-PROCESS ACCEPTED IN-PROCESS Attendee 2 reply 1204 now working on the 1205 task. 1206 5. IN-PROCESS IN-PROCESS IN-PROCESS Attendee 1 reply 1207 now working on the 1208 task. 1209 6. IN-PROCESS COMPLETED IN-PROCESS Attendee 1 reply 1210 Completed (overall 1211 status still 1212 IN-PROCESS). 1214 6. IN-PROCESS COMPLETED COMPLETED Attendee 2 reply 1215 Completed 1216 7. COMPLETED COMPLETED COMPLETED Organizer changes 1217 overall state once 1218 both attendees are 1219 finished. 1221 Note: The logic for determining the status change to the VTODO is 1222 determined by the task organizer based on the ATTENDEE status and 1223 other business logic. 1225 A.3. Failed Example 1227 Example of status changes for a task that fails. 1229 STATUS PARTSTAT Action 1230 ------ -------- ------ 1231 1. - - Organizer draft 1232 2. NEEDS-ACTION NEEDS-ACTION Organizer sends iTIP request 1233 3. NEEDS-ACTION ACCEPTED Attendee reply 1234 4. IN-PROCESS IN-PROCESS Attendee reply now working on the 1235 task 1236 5. IN-PROCESS FAILED Attendee reply task failed 1237 6. FAILED FAILED Organizer changes overall state 1239 Appendix B. Working Notes 1241 B.1. Advertising tasks 1243 Use VPOLL for advertising a task to a pool of possible ATTENDEEs and 1244 then select the respondent to assign one or more assignees. 1246 Introduce POLL-MODE:ASSIGNMENT 1248 Need to indicate number of assignees required. 1250 Potentially different types of response e.g. ACCEPT or DECLINE, or a 1251 weighting e.g. 0 - 100 1253 Take into FREEBUSY discussion. 1255 B.2. Subscribing to task updates 1257 Stakeholders should have the ability to subscribe to categories / 1258 types of tasks on an ongoing basis. Reference calendarserver.org 1259 notifications draft 1261 Appendix C. Change Log 1263 V01. 2015-08-23 AA 1265 o Highlighted use of ESTIMATED-DURATION for time planning. 1267 o Corrected PARTSTAT example section 5.1. Changed DECLINED to 1268 FAILED. 1270 o Replaced Task Mode AUTOMATIC-STATUS with CLIENT and SERVER modes. 1271 Also, clarified that task mode processing is only done on the 1272 organizer's copy. 1274 o Clarified responsibility for setting MODIFIED. 1276 o CalDAV support added. 1278 o Updated normative references. 1280 Authors' Addresses 1282 Adrian Apthorp 1283 DHL Express 1284 Fritz-Erler-Str. 5 1285 53113 Bonn 1286 Germany 1288 EMail: aapthorp@theiet.org 1289 URI: http://www.dhl.com 1291 Cyrus Daboo 1292 Apple Inc. 1293 1 Infinite Loop 1294 Cupertino, CA 95014 1295 USA 1297 EMail: cyrus@daboo.name 1298 URI: http://www.apple.com/ 1300 Mike Douglass 1301 Rensselaer Polytechnic Institute 1302 110 8th Street 1303 Troy, NY 12180 1304 USA 1306 EMail: douglm@rpi.edu 1307 URI: http://www.rpi.edu/