idnits 2.17.1 draft-brownlee-svg-rfc-13.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack a Security Considerations section. ** There are 3 instances of too long lines in the document, the longest one being 6 characters in excess of 72. == There are 1 instance of lines with non-RFC2606-compliant FQDNs in the document. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (October 16, 2015) is 3086 days in the past. Is this intentional? -- Found something which looks like a code comment -- if you have code sections in the document, please surround them with '' and '' lines. Checking references for intended status: Informational ---------------------------------------------------------------------------- == Missing Reference: 'SVG' is mentioned on line 79, but not defined -- Obsolete informational reference (is this intentional?): RFC 793 (Obsoleted by RFC 9293) Summary: 2 errors (**), 0 flaws (~~), 3 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group N. Brownlee 3 Internet-Draft The University of Auckland 4 Intended status: Informational IAB 5 Expires: April 18, 2016 October 16, 2015 7 SVG Drawings for RFCs: SVG 1.2 RFC 8 draft-brownlee-svg-rfc-13 10 Abstract 12 This document specifies SVG 1.2 RFC - an SVG profile for use in 13 diagrams that may appear in RFCs - and considers some of the issues 14 concerning the creation and use of such diagrams. 16 Status of This Memo 18 This Internet-Draft is submitted in full conformance with the 19 provisions of BCP 78 and BCP 79. 21 Internet-Drafts are working documents of the Internet Engineering 22 Task Force (IETF). Note that other groups may also distribute 23 working documents as Internet-Drafts. The list of current Internet- 24 Drafts is at http://datatracker.ietf.org/drafts/current/. 26 Internet-Drafts are draft documents valid for a maximum of six months 27 and may be updated, replaced, or obsoleted by other documents at any 28 time. It is inappropriate to use Internet-Drafts as reference 29 material or to cite them other than as "work in progress." 31 This Internet-Draft will expire on April 18, 2016. 33 Copyright Notice 35 Copyright (c) 2015 IETF Trust and the persons identified as the 36 document authors. All rights reserved. 38 This document is subject to BCP 78 and the IETF Trust's Legal 39 Provisions Relating to IETF Documents 40 (http://trustee.ietf.org/license-info) in effect on the date of 41 publication of this document. Please review these documents 42 carefully, as they describe your rights and restrictions with respect 43 to this document. Code Components extracted from this document must 44 include Simplified BSD License text as described in Section 4.e of 45 the Trust Legal Provisions and are provided without warranty as 46 described in the Simplified BSD License. 48 Table of Contents 50 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 51 2. SVG 1.2 RFC: An SVG profile for RFCs . . . . . . . . . . . . 3 52 2.1. Elements, properties and attributes allowed in SVG 1.2 53 RFC . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 54 3. How to create SVG drawings . . . . . . . . . . . . . . . . . 6 55 4. Accessibility Considerations . . . . . . . . . . . . . . . . 7 56 5. Meta-language for diagrams common in RFCs . . . . . . . . . . 8 57 5.1. Packet Layout Diagrams . . . . . . . . . . . . . . . . . 8 58 5.2. Sequence Diagrams (1) . . . . . . . . . . . . . . . . . . 9 59 5.3. Sequence Diagrams (2) . . . . . . . . . . . . . . . . . . 11 60 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 61 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 62 8. Revision History [RFC Editor please delete] . . . . . . . . . 14 63 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 64 9.1. Normative References . . . . . . . . . . . . . . . . . . 15 65 9.2. Informative References . . . . . . . . . . . . . . . . . 16 66 Appendix A. RELAX NG Compact (rnc) Schema for SVG 1.2 RFC . . . 17 67 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 58 69 1. Introduction 71 Over the last two years the RFC Editor has worked with the Internet 72 community to develop specifications for changes in the format of 73 RFCs. An outline of the resulting specifications was published as 74 [RFC6949] in May 2013. Since then a Design Team has been working 75 with the RFC Editor to flesh out those specifications. One aspect of 76 the changes is to allow line drawings in RFCs; [RFC6949] says 78 "Graphics may include ASCII art and a more complex form to be 79 defined, such as SVG line art [SVG]. Color and grayscale will not 80 be accepted. RFCs must correctly display in monochromatic black- 81 and-white to allow for monochrome displays, black-and-white 82 printing, and support for visual disabilities." 84 SVG (Scalable Vector Graphics) has been developed by W3C, the World 85 Wide Web Consortium; its current standard is SVG 1.1 Full 86 [W3C.REC-SVG11-20110816]. This document defines SVG 1.2 RFC, an SVG 87 profile (i.e. a subset of SVG) that is suitable for RFC line 88 drawings. 90 Note that in RFCs, the text provides normative descriptions of 91 protocols, systems, etc. Diagrams may be used to help explain 92 concepts more clearly, but they provide supporting detail, and should 93 not be considered to be complete specifications in themselves. 95 The details (particularly any vocabularies) described in this 96 document are expected to change based on experience gained in 97 implementing the RFC production center's toolset. Revised documents 98 will be published capturing those changes as the toolset is 99 completed. Other implementors must not expect those changes to 100 remain backwards-compatible with the details described in this 101 document. 103 2. SVG 1.2 RFC: An SVG profile for RFCs 105 As a starting point for SVG 1.2 RFC, the Design Team decided to use 106 SVG 1.2 Tiny [W3C.REC-SVGTiny12-20081222]. SVG 1.2 Tiny is an SVG 107 subset intended to be implemented on small, mobile devices such as 108 cellphones and smartphones. That should allow RFCs to be rendered 109 well on such devices, especially those that have small screens. 110 However, RFCs are self-contained documents that do not change once 111 they are published. The use of SVG drawings in RFCs is intended to 112 allow authors to create drawings that are simple to produce, and 113 easier to understand than our traditional 'ASCII Art' ones. In 114 short, we are also trying to improve access to the content in RFCs, 115 so SVG drawings need to be kept as simple as possible. 117 SVG can provide a complete User Interface, but within RFCs, all we 118 need are simple diagrams that do not change once the RFC is 119 published. Therefore, SVG RFC does not allow anything from the 120 following sections in SVG Tiny 1.2 [W3C.REC-SVGTiny12-20081222]: 122 12 Multimedia 123 13 Interactivity 124 15 Scripting 125 16 Animation 126 18 Metadata 127 19 Extensibility 129 Note that SVG Tiny 1.2 elements may have many properties or 130 attributes that are needed to support aspects of the above sections. 131 Those are not allowed in SVG 1.2 RFC. 133 Considering the other sections in SVG Tiny 1.2 134 [W3C.REC-SVGTiny12-20081222]: 136 9 Basic Shapes 137 10 Text 138 Everything in these sections is allowed in SVG 1.2 RFC. 140 11 Painting: Filling, Stroking, Colors and Paint Servers 141 Anything relating to 'color' is not allowed in SVG 1.2 RFC, 142 everything else is allowed. This is a requirement documented in 143 [RFC6949]. 145 14 Linking 146 SVG Tiny 1.2 allows internationalized IRIs in references. In 147 SVG 1.2 RFC such links must be ASCII only. That should not 148 cause problems, since one can just use the URI form of any IRI. 149 Authors should try to use links only to URIs that are long-term 150 stable. 152 17 Fonts 153 SVG 1.2 RFC only allows 'serif', 'sans-serif' and 'monospace' 154 generic font families from the WebFonts facility, described in 155 CSS 2.1, [W3C.REC-CSS2-20110607], section 15, Fonts. In 156 particular, the SVG 'font' element is not allowed. 158 2.1. Elements, properties and attributes allowed in SVG 1.2 RFC 160 Elements, properties and attributes selected for SVG 1.2 RFC from 161 [W3C.REC-SVGTiny12-20081222]. 163 In the list below, elements and properties are listed on the 164 left,and their allowed values are given in parentheses on the 165 right. 167 is the list of allowed colors, a black-and-white 168 subset of the SVG color names. 170