< draft-ietf-justfont-toplevel-00.txt		draft-ietf-justfont-toplevel-01.txt >
	Network Working Group C. Lilley		Network Working Group C. Lilley
	Internet-Draft W3C		Internet-Draft W3C
	Intended status: Standards Track January 29, 2016		Intended status: Standards Track February 24, 2016
	Expires: August 1, 2016		Expires: August 27, 2016
	The font Top Level Type		The font Top Level Type
	draft-ietf-justfont-toplevel-00		draft-ietf-justfont-toplevel-01
	Abstract		Abstract
	This memo serves to register and document the "font" Top Level Type,		This memo serves to register and document the "font" Top Level Type,
	under which the Internet Media subtypes for representation formats		under which the Internet Media subtypes for representation formats
	for fonts may be registered. This document also serves as a		for fonts may be registered. This document also serves as a
	registration application for a set of intended subtypes, which are		registration application for a set of intended subtypes, which are
	representative of some existing subtypes already registered under the		representative of some existing subtypes already in use, and
	"application" tree by their separate registrations.		currently registered under the "application" tree by their separate
			registrations.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on August 1, 2016.		This Internet-Draft will expire on August 27, 2016.
	Copyright Notice		Copyright Notice
	Copyright (c) 2016 IETF Trust and the persons identified as the		Copyright (c) 2016 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	1. Introduction		1. Specification development
			This section is non-normative. The source for this specification is
			maintained on GitHub [1]. The issues list [2] is also on GitHub.
			Discussion should be on the mailing list justfont@ietf.org [3].
			2. Introduction
	The process of setting type in computer systems and other forms of		The process of setting type in computer systems and other forms of
	text presentation systems uses fonts in order to provide visual		text presentation systems uses fonts in order to provide visual
	representations of the glyphs. Just as with images, for example,		representations of the glyphs. Just as with images, for example,
	there are a number of ways to represent the visual information of the		there are a number of ways to represent the visual information of the
	glyphs. Early font formats often used bitmaps, as these could have		glyphs. Early font formats often used bitmaps, as these could have
	been carefully tuned for maximum readability at a given size on low-		been carefully tuned for maximum readability at a given size on low-
	resolution displays. More recently, scalable vector outline fonts		resolution displays. More recently, scalable vector outline fonts
	have come into widespread use: in these fonts, the outlines of the		have come into widespread use: in these fonts, the outlines of the
	glyphs are described, and the presentation system renders the outline		glyphs are described, and the presentation system renders the outline
	skipping to change at page 2, line 31 ¶		skipping to change at page 2, line 37 ¶
	under which different representation formats of fonts may be		under which different representation formats of fonts may be
	registered (e.g. a bitmap or outline formats). It should be		registered (e.g. a bitmap or outline formats). It should be
	emphasized that, just as under the "image" top-level type one does		emphasized that, just as under the "image" top-level type one does
	not find registration for a specific image, for example, "The Night-		not find registration for a specific image, for example, "The Night-
	watch" (by Rembrandt) but instead "JPEG" (a compressed image data		watch" (by Rembrandt) but instead "JPEG" (a compressed image data
	representation format), so, under "font" one will not find "Courier"		representation format), so, under "font" one will not find "Courier"
	(the name of a popular font) but perhaps "TTF", "OTF" or "SFNT" (the		(the name of a popular font) but perhaps "TTF", "OTF" or "SFNT" (the
	names of commonly used TrueType and OpenType font formats as well as		names of commonly used TrueType and OpenType font formats as well as
	their higher-level wrapper format).		their higher-level wrapper format).
	2. Background and Justification		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
			"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
			document are to be interpreted as described in RFC 2119 [RFC2119].
			3. Background and Justification
	Historically there has not been a registration of formats for fonts.		Historically there has not been a registration of formats for fonts.
	Most recently, there have been several representation formats		Most recently, there have been several representation formats
	registered as MIME subtypes under the "application" top-level type.		registered as MIME subtypes under the "application" top-level type.
	However, with the rapid adoption of web fonts (based on the data from		However, with the rapid adoption of web fonts (based on the data from
	HTTP Archive [1] showing a huge increase in web font usage from 1% in		HTTP Archive [HTTP-Archive-Trends] showing a huge increase in web
	the end of 2010 to 50% across all sites in the beginning of 2015)		font usage from 1% in the end of 2010 to 50% across all sites in the
	custom fonts on the web have become a core web resource. As the in-		beginning of 2015) custom fonts on the web have become a core web
	depth analysis [2] shows, the lack of the intuitive top-level font		resource. As the in-depth analysis [Font-Media-Type-Analysis] shows,
	type is causing significant confusion among developers - while		the lack of the intuitive top-level font type is causing significant
	currently defined font subtypes are severely under-utilized there are		confusion among developers - while currently defined font subtypes
	many more sites that already use non-existent (but highly intuitive)		are severely under-utilized there are many more sites that already
	media types such as "font/woff", "font/ttf" and "font/truetype". At		use non-existent (but highly intuitive) media types such as "font/
	the same time, the majority of sites resort to using generic types		woff", "font/ttf" and "font/truetype". At the same time, the
	such as "application/octet-stream", "text/plain" and "text/html"; or		majority of sites resort to using generic types such as "application/
	use unregistrable types such as "application/x-font-ttf".		octet-stream", "text/plain" and "text/html"; or use unregistrable
			types such as "application/x-font-ttf".
	Contrary to our expectations, the officially defined IANA subtypes		Contrary to our expectations, the officially defined IANA subtypes
	such as "application/font-woff" and "application/font-sfnt" see a		such as "application/font-woff" and "application/font-sfnt" see a
	very limited use - their adoption rates trail far behind as the		very limited use - their adoption rates trail far behind as the
	actual use of web fonts continues to increase. The members of the		actual use of web fonts continues to increase. The members of the
	W3C WebFonts WG believe the use of "application" top-level type is		W3C WebFonts WG believe the use of "application" top-level type is
	not ideal. First, the "application" sub-tree is treated (correctly)		not ideal. First, the "application" sub-tree is treated (correctly)
	with great caution with respect to viruses and other active code.		with great caution with respect to viruses and other active code.
	Secondly, the lack of a top-level type means that there is no		Secondly, the lack of a top-level type means that there is no
	opportunity to have a common set of optional attributes, such as are		opportunity to have a common set of optional attributes, such as are
	skipping to change at page 3, line 28 ¶		skipping to change at page 3, line 39 ¶
	intuitive media types for images that caused the widespread adoption		intuitive media types for images that caused the widespread adoption
	of IANA's recommendations, where the correct usage of existing media		of IANA's recommendations, where the correct usage of existing media
	types reaches over 97% for all subtypes in the "image" tree. The WG		types reaches over 97% for all subtypes in the "image" tree. The WG
	believes that, considering a rapid adoption of fonts on the web, the		believes that, considering a rapid adoption of fonts on the web, the
	registration of the top-level media type for fonts along with the		registration of the top-level media type for fonts along with the
	intuitive set of subtypes that reflect popular and widely used data		intuitive set of subtypes that reflect popular and widely used data
	formats would further stimulate the adoption of web fonts,		formats would further stimulate the adoption of web fonts,
	significantly simplify web server configuration process and		significantly simplify web server configuration process and
	facilitate the proper use of IANA media type recommendations.		facilitate the proper use of IANA media type recommendations.
	3. Security considerations		4. Security considerations
	Fonts are interpreted data structures that represent collections of		Fonts are interpreted data structures that represent collections of
	different tables containing data that represent different types of		different tables containing data that represent different types of
	information, including glyph outlines in various formats, hinting		information, including glyph outlines in various formats, hinting
	instructions, metrics and layout information for multiple languages		instructions, metrics and layout information for multiple languages
	and writing systems, rules for glyph substitution and positioning,		and writing systems, rules for glyph substitution and positioning,
	etc. Depending on the format used to represent the glyph data the		etc. Depending on the format used to represent the glyph data the
	font may contain TrueType, PostScript or SVG outlines and their		font may contain TrueType, PostScript or SVG outlines and their
	respective hint instructions, where applicable. There are many		respective hint instructions, where applicable. There are many
	existing, already standardized font table tags and formats that allow		existing, already standardized font table tags and formats that allow
	skipping to change at page 4, line 29 ¶		skipping to change at page 4, line 40 ¶
	Widespread use of fonts as necessary component of visual content		Widespread use of fonts as necessary component of visual content
	presentation warrants that a careful attention should be given to		presentation warrants that a careful attention should be given to
	security considerations whenever a font is either embedded into an		security considerations whenever a font is either embedded into an
	electronic document or transmitted alongside media content as a		electronic document or transmitted alongside media content as a
	linked resource. While many existing font formats provide certain		linked resource. While many existing font formats provide certain
	levels of protection of data integrity (such mechanisms include e.g.		levels of protection of data integrity (such mechanisms include e.g.
	checksums and digital signatures), font data formats provide neither		checksums and digital signatures), font data formats provide neither
	privacy nor confidentiality protection internally; if needed, such		privacy nor confidentiality protection internally; if needed, such
	protection should be provided externally.		protection should be provided externally.
	4. Definition and encoding		5. IANA Considerations
			This specification requires IANA to modify the rules for the existing
			Internet Media Types registry by adding a new font top-level type in
			the standards tree, and registering several subtypes.
			6. Definition and encoding
	The "font" as the primary media content type indicates that the		The "font" as the primary media content type indicates that the
	content identified by it requires certain graphic subsystem such as		content identified by it requires certain graphic subsystem such as
	font rendering engine (and, in some cases, text layout and shaping		font rendering engine (and, in some cases, text layout and shaping
	engine) to process font data, which in turn may require certain level		engine) to process font data, which in turn may require certain level
	of hardware capabilities such as certain levels of CPU performance		of hardware capabilities such as certain levels of CPU performance
	and available memory. The "font" media type does not provide any		and available memory. The "font" media type does not provide any
	specific information about the underlying data format and how the		specific information about the underlying data format and how the
	font information should be interpreted - the subtypes defined within		font information should be interpreted - the subtypes defined within
	a "font" tree will name the specific font formats. Unrecognized sub-		a "font" tree will name the specific font formats. Unrecognized sub-
	types of "font" should be treated as "application/octet-stream".		types of "font" should be treated as "application/octet-stream".
	Implementations may pass unrecognized subtypes to a common font-		Implementations may pass unrecognized subtypes to a common font-
	handling system, if such system is available.		handling system, if such system is available.
	5. Defined subtypes		7. Defined subtypes
	In this section the initial entries under the top-level 'font' MIME		In this section the initial entries under the top-level 'font' MIME
	type are documented. They also serve as examples for future		type are documented. They also serve as examples for future
	registrations.		registrations.
	5.1. Generic SFNT font type		For each subtype, an @font-face format identifer is defined. This
			for use with the @font-face src descriptor, defined by the CSS3 Fonts
			specification [W3C.CR-css-fonts-3-20131003].
			7.1. Generic SFNT font type
	Type name: font		Type name: font
	Subtype name: sfnt		Subtype name: sfnt
	Required parameters: None.		Required parameters: None.
	Optional parameters:		Optional parameters:
	1) Name: Outlines Value: TTF, CFF, SVG		1) Name: Outlines Value: TTF, CFF, SVG
	This parameter can be used to specify the type of outlines		This parameter can be used to specify the type of outlines
	supported by the font. Value "TTF" shall be used when a font		supported by the font. Value "TTF" shall be used when a font
	resource contains glyph outlines in TrueType format, value		resource contains glyph outlines in TrueType format, value
	"CFF" shall be used to identify fonts containing PostScript/CFF		"CFF" shall be used to identify fonts containing PostScript/CFF
	outlines, and value SVG shall be used to identify fonts that		outlines, and value SVG shall be used to identify fonts that
	include SVG outlines. TTF, CFF or SVG outlines can be present		include SVG outlines. TTF, CFF or SVG outlines can be present
	in various combinations in the same font file, therefore,		in various combinations in the same font file, therefore, this
	multiple values for the same optional parameter may be defined.		optional parameter is a list containing one or more items,
			separated by commas, with optional whitespace. Order in the
			list is not significant.
	2) Name: Layout		2) Name: Layout
	Value: OTF, AAT, SIL		Value: OTL, AAT, SIL
	This parameter identifies the type of implemented support for		This parameter identifies the type of implemented support for
	advanced text layout features. The predefined values "OTF",		advanced text layout features. The predefined values "OTL",
	"AAT" and " SIL" respectively indicate support for OpenType		"AAT" and "SIL" respectively indicate support for OpenType text
	text layout, Apple Advanced Typography or Graphite SIL. More		layout, Apple Advanced Typography or Graphite SIL. More than
	than one shaping and layout mechanism may be supported by the		one shaping and layout mechanism may be supported by the same
	same font file, therefore, multiple values for the same		font file, therefore, this optional parameter is a list
	optional parameter may be defined.		containing one or more items, separated by commas, with
			optional whitespace. Order in the list is not significant.
	Encoding considerations: Binary.		Encoding considerations: Binary.
	Interoperability considerations: As it was noted in the first		Interoperability considerations: As it was noted in the first
	paragraph of the "Security considerations" section, the same font		paragraph of the "Security considerations" section, the same font
	format wrapper can be used to encode fonts with different types of		format wrapper can be used to encode fonts with different types of
	glyph data represented as either TrueType or PostScript (CFF)		glyph data represented as either TrueType or PostScript (CFF)
	outlines. Existing font rendering engines may not be able to		outlines. Existing font rendering engines may not be able to
	process some of the particular outline formats, and downloading a		process some of the particular outline formats, and downloading a
	font resource that contains unsupported glyph data format would		font resource that contains unsupported glyph data format would
	skipping to change at page 6, line 10 ¶		skipping to change at page 6, line 32 ¶
	format of the glyph outline data within a font using an optional		format of the glyph outline data within a font using an optional
	parameter, and allow applications to make decisions about		parameter, and allow applications to make decisions about
	downloading a particular font resource sooner. Similar, another		downloading a particular font resource sooner. Similar, another
	optional parameter is suggested to identify the type of text		optional parameter is suggested to identify the type of text
	shaping and layout mechanism that is supported by a font. Please		shaping and layout mechanism that is supported by a font. Please
	note that as new outline formats and text shaping mechanisms may		note that as new outline formats and text shaping mechanisms may
	be defined in the future, the set of allowed values for two		be defined in the future, the set of allowed values for two
	optional parameters defined by this section may be extended.		optional parameters defined by this section may be extended.
	Published specification: ISO/IEC 14496-22 "Open Font Format" (OFF)		Published specification: ISO/IEC 14496-22 "Open Font Format" (OFF)
	specification being developed by ISO/IEC SC29/WG11.		specification [ISO.14496-22.2015] being developed by ISO/IEC SC29/
			WG11.
	Applications that use this media type: Any and all applications that		Applications that use this media type: Any and all applications that
	are able to create, edit or display textual media content.		are able to create, edit or display textual media content.
	Additional information:		Additional information:
	Magic number(s): The TrueType fonts and OFF / OpenType fonts		Magic number(s): The TrueType fonts and OFF / OpenType fonts
	containing TrueType outlines should use 0x00010000 as the		containing TrueType outlines should use 0x00010000 as the
	'sfnt' version number.		'sfnt' version number.
	skipping to change at page 7, line 5 ¶		skipping to change at page 7, line 27 ¶
	Intended usage: COMMON		Intended usage: COMMON
	Restrictions on usage: None		Restrictions on usage: None
	Author: The ISO/IEC 14496-22 "Open Font Format" specification is a		Author: The ISO/IEC 14496-22 "Open Font Format" specification is a
	product of the ISO/IEC JTC1 SC29/WG11.		product of the ISO/IEC JTC1 SC29/WG11.
	Change controller: The ISO/IEC has change control over this		Change controller: The ISO/IEC has change control over this
	specification.		specification.
	5.2. TTF font type		7.2. TTF font type
	Type name: font		Type name: font
	Subtype name: ttf		Subtype name: ttf
	Required parameters: None.		Required parameters: None.
	Optional parameters:		Optional parameters:
	Name: Layout Value: OTF, AAT, SIL		Name: Layout Value: OTL, AAT, SIL
	This parameter identifies the type of support mechanism for		This parameter identifies the type of support mechanism for
	advanced text layout features. The predefined values "OTF",		advanced text layout features. The predefined values "OTL",
	"AAT" and " SIL" respectively indicate support for OpenType		"AAT" and "SIL" respectively indicate support for OpenType text
	text layout, Apple Advanced Typography or Graphite SIL. More		layout, Apple Advanced Typography or Graphite SIL. More than
	than one shaping and layout mechanism may be supported by the		one shaping and layout mechanism may be supported by the same
	same font file, therefore, multiple values for the same		font file, therefore, this optional parameter is a list
	optional parameter may be defined.		containing one or more items, separated by commas, with
			optional whitespace. Order in the list is not significant.
	Encoding considerations: Binary.		Encoding considerations: Binary.
	Interoperability considerations: As was noted in the first paragraph		Interoperability considerations: As was noted in the first paragraph
	of the "Security considerations" section, the same font format can		of the "Security considerations" section, the same font format can
	be used to encode fonts supporting different types of outlines		be used to encode fonts supporting different types of outlines
	and/or text shaping and layout mechanisms. Existing font		and/or text shaping and layout mechanisms. Existing font
	rendering engine implementations may not be able to process some		rendering engine implementations may not be able to process some
	of the particular layout table formats, and downloading a font		of the particular layout table formats, and downloading a font
	resource that contains unsupported text shaping mechanism would		resource that contains unsupported text shaping mechanism would
	result in inability of applications to display text properly.		result in inability of applications to display text properly.
	Therefore, it would be extremely useful to clearly identify the		Therefore, it would be extremely useful to clearly identify the
	supported text shaping and layout data within a font using an		supported text shaping and layout data within a font using an
	optional parameter, and allow applications to make decisions about		optional parameter, and allow applications to make decisions about
	downloading a particular font resource sooner. Please note that		downloading a particular font resource sooner. Please note that
	as new text shaping mechanisms may be defined in the future, the		as new text shaping mechanisms may be defined in the future, the
	set of allowed values for the optional parameter defined by this		set of allowed values for the optional parameter defined by this
	section may be extended.		section may be extended.
	Published specification: ISO/IEC 14496-22 "Open Font Format" (OFF)		Published specification: ISO/IEC 14496-22 "Open Font Format" (OFF)
	specification being developed by ISO/IEC SC29/WG11.		specification [ISO.14496-22.2015] being developed by ISO/IEC SC29/
			WG11.
	Applications that use this media type: Any and all applications that		Applications that use this media type: Any and all applications that
	are able to create, edit or display textual media content.		are able to create, edit or display textual media content.
	Additional information:		Additional information:
	Magic number(s): The TrueType fonts and OFF / OpenType fonts		Magic number(s): The TrueType fonts and OFF / OpenType fonts
	containing TrueType outlines should use 0x00010000 as the		containing TrueType outlines should use 0x00010000 as the
	'sfnt' version number.		'sfnt' version number.
	skipping to change at page 8, line 28 ¶		skipping to change at page 9, line 4 ¶
	@font-face Format: truetype		@font-face Format: truetype
	Fragment Identifiers none.		Fragment Identifiers none.
	Person & email address to contact for further information: Vladimir		Person & email address to contact for further information: Vladimir
	Levantovsky (vladimir.levantovsky@monotype.com).		Levantovsky (vladimir.levantovsky@monotype.com).
	Intended usage: COMMON		Intended usage: COMMON
	Restrictions on usage: None		Restrictions on usage: None
	Author: The ISO/IEC 14496-22 "Open Font Format" specification is a		Author: The ISO/IEC 14496-22 "Open Font Format" specification is a
	product of the ISO/IEC JTC1 SC29/WG11.		product of the ISO/IEC JTC1 SC29/WG11.
	Change controller: The ISO/IEC has change control over this		Change controller: The ISO/IEC has change control over this
	specification.		specification.
	5.3. OTF font type		7.3. OTF font type
	Type name: font		Type name: font
	Subtype name: otf		Subtype name: otf
	Required parameters: None.		Required parameters: None.
	Optional parameters		Optional parameters
	Name: Outlines Value: TTF, CFF, SVG		Name: Outlines Value: TTF, CFF, SVG
	This parameter can be used to specify the type of outlines		This parameter can be used to specify the type of outlines
	supported by the font. Value "TTF" shall be used when a font		supported by the font. Value "TTF" shall be used when a font
	resource contains glyph outlines in TrueType format, value		resource contains glyph outlines in TrueType format, value
	"CFF" shall be used to identify fonts containing PostScript/CFF		"CFF" shall be used to identify fonts containing PostScript/CFF
	outlines, and value SVG shall be used to identify fonts that		outlines, and value SVG shall be used to identify fonts that
	include SVG outlines. TTF, CFF or SVG outlines can be present		include SVG outlines. TTF, CFF or SVG outlines can be present
	in various combinations in the same font file, therefore,		in various combinations in the same font file, therefore, this
	multiple values for the same optional parameter may be defined.		optional parameter is a list containing one or more items,
			separated by commas, with optional whitespace. Order in the
			list is not significant.
	Encoding considerations: Binary.		Encoding considerations: Binary.
	Interoperability considerations: As it was noted in the first		Interoperability considerations: As it was noted in the first
	paragraph of the "Security considerations" section, the same font		paragraph of the "Security considerations" section, the same font
	format can be used to encode fonts with different types of glyph		format can be used to encode fonts with different types of glyph
	data represented as either TrueType, PostScript (CFF) or SVG		data represented as either TrueType, PostScript (CFF) or SVG
	outlines. Existing font rendering engines may not be able to		outlines. Existing font rendering engines may not be able to
	process some of the particular outline formats, and downloading a		process some of the particular outline formats, and downloading a
	font resource that contains unsupported glyph data format would		font resource that contains unsupported glyph data format would
	result in inability of application to render and display text.		result in inability of application to render and display text.
	Therefore, it would be extremely useful to clearly identify the		Therefore, it would be extremely useful to clearly identify the
	format of the glyph outline data within a font using an optional		format of the glyph outline data within a font using an optional
	parameter, and allow applications to make decisions about		parameter, and allow applications to make decisions about
	downloading a particular font resource sooner. Please note that		downloading a particular font resource sooner. Please note that
	as new outline formats may be defined in the future, the set of		as new outline formats may be defined in the future, the set of
	allowed values for the optional parameter defined in this section		allowed values for the optional parameter defined in this section
	may be extended.		may be extended.
	Published specification: ISO/IEC 14496-22 "Open Font Format" (OFF)		Published specification: ISO/IEC 14496-22 "Open Font Format" (OFF)
	specification being developed by ISO/IEC SC29/WG11.		specification [ISO.14496-22.2015] being developed by ISO/IEC SC29/
			WG11.
	Applications that use this media type: Any and all applications that		Applications that use this media type: Any and all applications that
	are able to create, edit or display textual media content.		are able to create, edit or display textual media content.
	Additional information:		Additional information:
	Magic number(s): The TrueType fonts and OFF / OpenType fonts		Magic number(s): The TrueType fonts and OFF / OpenType fonts
	containing TrueType outlines should use 0x00010000 as the		containing TrueType outlines should use 0x00010000 as the
	'sfnt' version number.		'sfnt' version number.
	The OFF / OpenType fonts containing CFF data should use the tag		The OFF / OpenType fonts containing CFF outlines should use the
	'OTTO' as 'sfnt' version number.		tag 'OTTO' as 'sfnt' version number. There is no magic number
			for SVG outlines; these are always accompanied by either
			TrueType or CFF outlines and thus use the corresponding magic
			number.
	File extension(s): Font file extensions used for OFF / OpenType		File extension(s): Font file extensions used for OFF / OpenType
	fonts: .ttf, .otf		fonts: .ttf, .otf
	Typically, .ttf extension is only used for fonts containing		Typically, .ttf extension is only used for fonts containing
	TrueType outlines, while .otf extension can be used for any		TrueType outlines, while .otf extension can be used for any
	OpenType/OFF font, either with TrueType, CFF or SVG outlines.		OpenType/OFF font, either with TrueType, CFF or SVG outlines.
	Macintosh file type code(s): (no code specified)		Macintosh file type code(s): (no code specified)
	skipping to change at page 10, line 18 ¶		skipping to change at page 11, line 5 ¶
	Intended usage: COMMON		Intended usage: COMMON
	Restrictions on usage: None		Restrictions on usage: None
	Author: The ISO/IEC 14496-22 "Open Font Format" specification is a		Author: The ISO/IEC 14496-22 "Open Font Format" specification is a
	product of the ISO/IEC JTC1 SC29/WG11.		product of the ISO/IEC JTC1 SC29/WG11.
	Change controller: The ISO/IEC has change control over this		Change controller: The ISO/IEC has change control over this
	specification.		specification.
	5.4. WOFF 1.0		7.4. Collection font type
			Type name: font
			Subtype name: collection
			Required parameters: None.
			Optional parameters
			Name: Outlines Value: TTF, CFF, SVG
			This parameter can be used to specify the type of outlines
			supported by the font. Value "TTF" shall be used when a font
			resource contains glyph outlines in TrueType format, value
			"CFF" shall be used to identify fonts containing PostScript/CFF
			outlines, and value SVG shall be used to identify fonts that
			include SVG outlines. TTF, CFF or SVG outlines can be present
			in various combinations in the same font file, therefore, this
			optional parameter is a list containing one or more items,
			separated by commas, with optional whitespace. Order in the
			list is not significant.
			Encoding considerations: Binary.
			Interoperability considerations: As it was noted in the first
			paragraph of the "Security considerations" section, the same font
			format can be used to encode fonts with different types of glyph
			data represented as either TrueType, PostScript (CFF) or SVG
			outlines. Existing font rendering engines may not be able to
			process some of the particular outline formats, and downloading a
			font resource that contains unsupported glyph data format would
			result in inability of application to render and display text.
			Therefore, it would be extremely useful to clearly identify the
			format of the glyph outline data within a font using an optional
			parameter, and allow applications to make decisions about
			downloading a particular font resource sooner. Please note that
			as new outline formats may be defined in the future, the set of
			allowed values for the optional parameter defined in this section
			may be extended.
			Published specification: ISO/IEC 14496-22 "Open Font Format" (OFF)
			specification [ISO.14496-22.2015] being developed by ISO/IEC SC29/
			WG11.
			Applications that use this media type: Any and all applications that
			are able to create, edit or display textual media content.
			Additional information:
			Magic number(s): The TrueType fonts and OFF / OpenType fonts
			containing TrueType outlines should use 0x00010000 as the
			'sfnt' version number.
			The OFF / OpenType fonts containing CFF outlines should use the
			tag 'OTTO' as 'sfnt' version number. There is no magic number
			for SVG outlines; these are always accompanied by either
			TrueType or CFF outlines and thus use the corresponding magic
			number.
			File extension(s): Font file extensions used for OFF / TrueType
			and OpenType fonts: .ttc
			Macintosh file type code(s): (no code specified)
			@font-face Format: collection
			Fragment Identifiers A positive integer. For example, #2 refers
			to the second font in the collection. If a fragment is not
			specified, it is the same as #1 i.e. the first font in the
			collection.
			Person & email address to contact for further information: Vladimir
			Levantovsky (vladimir.levantovsky@monotype.com).
			Intended usage: COMMON
			Restrictions on usage: None
			Author: The ISO/IEC 14496-22 "Open Font Format" specification is a
			product of the ISO/IEC JTC1 SC29/WG11.
			Change controller: The ISO/IEC has change control over this
			specification.
			7.5. WOFF 1.0
	Type name: font		Type name: font
	Subtype name: woff		Subtype name: woff
	Required parameters: None.		Required parameters: None.
	Optional parameters: None.		Optional parameters: None.
	Encoding considerations: Binary.		Encoding considerations: Binary.
	Interoperability considerations: None.		Interoperability considerations: None.
	Published specification: This media type registration updates the		Published specification: This media type registration updates the
	WOFF specification [3] at W3C.		WOFF specification [W3C.REC-WOFF-20121213] at W3C.
	Applications that use this media type: WOFF is used by Web browsers,		Applications that use this media type: WOFF is used by Web browsers,
	often in conjunction with HTML and CSS.		often in conjunction with HTML and CSS.
	Additional information:		Additional information:
	Magic number(s): The signature field in the WOFF header MUST		Magic number(s): The signature field in the WOFF header MUST
	contain the "magic number" 0x774F4646		contain the "magic number" 0x774F4646
	File extension(s): woff		File extension(s): woff
	skipping to change at page 11, line 18 ¶		skipping to change at page 13, line 41 ¶
	Intended usage: COMMON		Intended usage: COMMON
	Restrictions on usage: None		Restrictions on usage: None
	Author: The WOFF specification is a work product of the World Wide		Author: The WOFF specification is a work product of the World Wide
	Web Consortium's WebFonts Working Group.		Web Consortium's WebFonts Working Group.
	Change controller: The W3C has change control over this		Change controller: The W3C has change control over this
	specification.		specification.
	5.5. WOFF 2.0		7.6. WOFF 2.0
	Type name: font		Type name: font
	Subtype name: woff2		Subtype name: woff2
	Required parameters: None.		Required parameters: None.
	Optional parameters: None.		Optional parameters: None.
	Encoding considerations: Binary.		Encoding considerations: Binary.
	Interoperability considerations: WOFF 2.0 is an improvement on WOFF		Interoperability considerations: WOFF 2.0 is an improvement on WOFF
	1.0. The two formats have different Internet Media Types,		1.0. The two formats have different Internet Media Types,
	different @font-face formats, and may be used in parallel.		different @font-face formats, and may be used in parallel.
	Published specification: This media type registration is extracted		Published specification: This media type registration is extracted
	from the WOFF 2.0 specification [4] at W3C.		from the WOFF 2.0 specification [W3C.WD-WOFF2-20150414] at W3C.
	Applications that use this media type: WOFF 2.0 is used by Web		Applications that use this media type: WOFF 2.0 is used by Web
	browsers, often in conjunction with HTML and CSS.		browsers, often in conjunction with HTML and CSS.
	Additional information:		Additional information:
	Magic number(s): The signature field in the WOFF header MUST		Magic number(s): The signature field in the WOFF header MUST
	contain the "magic number" 0x774F4632 ('wOF2')		contain the "magic number" 0x774F4632 ('wOF2')
	File extension(s): woff2		File extension(s): woff2
	Macintosh file type code(s): (no code specified)		Macintosh file type code(s): (no code specified)
	Macintosh Universal Type Identifier code: "org.w3c.woff2"		Macintosh Universal Type Identifier code: "org.w3c.woff2"
	@font-face Format: woff2		@font-face Format: woff2
	Fragment Identifiers none.
			Fragment Identifiers Optional, for collections encoded as WOFF
			2.0. A positive integer. For example, #2 refers to the second
			font in the collection. If a fragment is not specified, it is
			the same as #1 i.e. the first font in the collection (or the
			only font, if it is not a collection). If a fragment is
			specified, and the WOFF does not encode a collection, the
			fragment is ignored.
	Person & email address to contact for further information: Chris		Person & email address to contact for further information: Chris
	Lilley (www-font@w3.org).		Lilley (www-font@w3.org).
	Intended usage: COMMON		Intended usage: COMMON
	Restrictions on usage: None		Restrictions on usage: None
	Author: The WOFF2 specification is a work product of the World Wide		Author: The WOFF2 specification is a work product of the World Wide
	Web Consortium's WebFonts Working Group.		Web Consortium's WebFonts Working Group.
	Change controller: The W3C has change control over this		Change controller: The W3C has change control over this
	specification.		specification.
	6. References		8. References
	6.1. URIs		8.1. Normative References
	[1] http://httparchive.org/		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	trends.php?s=All&minlabel=Nov+15+2010&maxlabel=Feb+15+2015		Requirement Levels", BCP 14, RFC 2119,
			DOI 10.17487/RFC2119, March 1997,
			<http://www.rfc-editor.org/info/rfc2119>.
	[2] http://goo.gl/zbDhUN		[W3C.CR-css-fonts-3-20131003]
			Daggett, J., "CSS Fonts Module Level 3", World Wide Web
			Consortium CR CR-css-fonts-3-20131003, October 2013,
			<http://www.w3.org/TR/2013/CR-css-fonts-3-20131003>.
	[3] http://www.w3.org/TR/WOFF		[ISO.14496-22.2015]
			International Organization for Standardization, "Coding of
			audio-visual objects Part 22: Open Font Format",
			ISO Standard 14496-22, 10 2015,
			<http://standards.iso.org/ittf/PubliclyAvailableStandards/
			c066391_ISO_IEC_14496-22_2015.zip>.
	[4] http://www.w3.org/TR/WOFF2		[W3C.REC-WOFF-20121213]
			Kew, J., Leming, T., and E. Blokland, "WOFF File Format
			1.0", World Wide Web Consortium Recommendation REC-WOFF-
			20121213, December 2012,
			<http://www.w3.org/TR/2012/REC-WOFF-20121213>.
			[W3C.WD-WOFF2-20150414]
			Levantovsky, V. and R. Levien, "WOFF File Format 2.0",
			World Wide Web Consortium WD WD-WOFF2-20150414, April
			2015, <http://www.w3.org/TR/2015/WD-WOFF2-20150414>.
			8.2. Informative References
			[HTTP-Archive-Trends]
			Kuetell, D., "HTTP Archive trend analysis", March 2015,
			<http://httparchive.org/trends.php?s=All&minlabel=Nov+15+2
			010&maxlabel=Feb+15+2015#perFonts>.
			[Font-Media-Type-Analysis]
			Kuetell, D., "Web Font Media Type (mime type) Analysis
			2015", 2015, <http://goo.gl/zbDhUN>.
			8.3. URIs
			[1] https://github.com/svgeesus/ietf-justfont
			[2] https://github.com/svgeesus/ietf-justfont/issues
			[3] mailto:justfont@ietf.org
	Author's Address		Author's Address
	Chris Lilley		Chris Lilley
	W3C		W3C
	2004 Route des Lucioles		2004 Route des Lucioles
	Sophia Antipolis 06902		Sophia Antipolis 06902
	France		France
	Email: chris@w3.org		Email: chris@w3.org
End of changes. 35 change blocks.
	61 lines changed or deleted		224 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/