faq-ja - Revision history

Tantek: rm ref to not even half-constructed 'notable-users' page which was an unsustainable/unmaintained odd subset of examples/implementations

2012-01-24T05:58:29Z

rm ref to not even half-constructed 'notable-users' page which was an unsustainable/unmaintained odd subset of examples/implementations

← Older revision		Revision as of 05:58, 24 January 2012
Line 33:		Line 33:
	===Q: ''Who uses microformats?'' ===		===Q: ''Who uses microformats?'' ===

	A: See a list of ~~[[notable-users\|some notable users]];~~ [[examples-in-wild\|~~other microformat users~~]] and [[implementations\|tools using microformats]].		A: See a list of [[examples-in-wild\|sites using microformats]] and [[implementations\|tools using microformats]].

	===Q: ''When should I use a microformat? What are they for?"===		===Q: ''When should I use a microformat? What are they for?"===

Brian: Reverted edits by ViracCacna (Talk) to last version by Brian

2009-01-08T10:09:29Z

Reverted edits by ViracCacna (Talk) to last version by Brian

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ViracCacna: monorbasd

2009-01-08T05:53:05Z

monorbasd

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Brian: Reverted edits by BocpaSrori (Talk) to last version by IwaiMasaharu

2008-12-20T22:16:44Z

Reverted edits by BocpaSrori (Talk) to last version by IwaiMasaharu

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BocpaSrori: delricdomr

2008-12-20T04:12:50Z

delricdomr

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IwaiMasaharu: sync: english: 10:56, 14 Oct 2007

2007-10-27T22:05:49Z

sync: english: 10:56, 14 Oct 2007

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Tantek: Reverted edit of ZbzYc4, changed back to last version by RyanKing

2007-06-13T15:36:37Z

Reverted edit of ZbzYc4, changed back to last version by RyanKing

← Older revision		Revision as of 15:36, 13 June 2007
Line 158:		Line 158:


	== <code>		== <code><div></code>と<code><span></code>のセマンティクス ==

			===''Q. Is it semantically meaningless to use divs?'' ===

			A. Yes, both <code><div></code> and <code><span></code> have nearly no semantics. <code><div></code> can be used to represent a "division" of the page content. Similarly <code><span></code> can be used to reperesent that that "span" of text has some meaning, but the specifics of what that meaning is undefined by the <code><span></code>.


			===''Q. Does the use of <code><div></code> and <code><span></code> elements add any semantics to web pages?''===

			A. According to the [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.4 HTML 4 spec], <code><div></code> and <code><span></code> "offer a generic mechanism for adding structure to documents." Their only meaning is in dividing documents into sections, and as such, their presence implies that the content within has a specific, but undefined by the element markup, semantic. Thus they are nearly semantic-free.


			===''Q. Why do the examples on the wiki use <code class="element"><span></code> and <code class="element"><div></code> for nearly everything?''===

			A. <code class="element"><span></code> and <code class="element"><div></code> are generic elements in HTML. When you use microformats, you should pick the most specific semantic element available for the semantics you are trying to express. You might, for example, apply <code>class="vevent"</code> to a <code><nowiki><tr></nowiki></code>, or <code>class="vcard"</code> to a <code><nowiki><p></nowiki></code>.

			== classのセマンティクス ==

			===Q. ''How will microformat class names impact page size?''===

			A. You probably won't notice any impact on page size when authoring with microformats. Our experience is that people use comparably sized class names, and [[semantic-class-names\|semantic class names]] are now considered an industry best practice. Some sites are successfully publishing millions of microformats, and we haven't heard any complaints yet. You are more likely to gain space savings by more fully adopting [[microformats#the_microformats_principles\|the principles of microformats]], and eliminating tables for layout.
			<span class="todo">''TODO: Consider creating a new section for web authoring tips? Or at least linking to another site that advocates good authorship.''</span>

			===Q. ''1つの要素に複数のclass名を付けることはできますか?''===

			A. できます。class属性の値は、空白区切りを入れることで複数のclass名を書くことができます。例えば次のようになります。
			<p class="todo idea">Write high quality and simple mark-up.</p>

			W3C HTML 4.01 Specificationのclass属性についての記述も見てください: [http://www.w3.org/TR/html401/struct/global.html#adef-class 7.5.2 Element identifiers: the id and class attributes]

			===Q. ''Do (X)HTML class names have semantics?''===

			A. The HTML4 specification does not define any particular class values [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF], nor does it define any particular semantic for class values [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF], except that they "may be used for general user agent processing" [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF]. However, the [http://www.w3.org/TR/WD-htmllink-970328#profile" draft of "Hypertext Links in HTML"], allows for a "profile" to define meanings for those classes. [http://gmpg.org/xmdp/ XMDP] is a format for defining meta data profiles for (X)HTML, and thus an XMDP profile can be used to define the meanings of class names.

			See also:
			* [http://tantek.com/log/2002/12.html#L20021216 A Touch Of Class]
			* [http://www.w3.org/TR/WD-htmllink-970328 Hypertext Links in HTML]

			===Q. ''I thought one of the main goals of CSS was to separate data from presentation. Isn’t this sneaking presentation back into data?''===

			A. This is a quite commonly expressed objection to the way microformats uses class, but it's based on a misunderstanding of the way the class attribute in HTML was designed. Yes, class is very commonly,and appropriately used by web designers in conjunction with CSS to style pages, and in truth, it is often overused for that, but despite this, class, according to the HTML specification "has several roles in HTML", including [http://www.w3.org/TR/html4/struct/global.html#h-7.5.2 "for general purpose processing by user agents"].

			Microformats utilize this second aspect of the class (and id) attribute, and do so legitimately. It is not an abuse of the class or id attribute to use it to add semantic context to a document. Nor is the use of class in and of itself presentational - in fact, it is an important mechanism for separating presentation from structured content.

			For some more on using class semantically, here are some articles

			* [http://meyerweb.com/eric/thoughts/2004/07/18/competent-classing Competent Classing by Eric Meyer]
			* [http://www.w3.org/QA/Tips/goodclassnames Use class with semantics in mind, W3C]
			* [http://tantek.com/log/2004/07.html#d20t2359 More about the class attribute, Tantek Çelik]

			== microformatsとspam ==
			===''Q. Given that Google now looks at hidden content as potential spam, will invisible microformats be considered spam?''===

			A. It is advisable not to hide information in your site, regardless of whether it is microformated or not. Microformats provide a mechanism for marking up ''visible'' content. Any mechanism for embedding ''invisible'' or hidden content risks being considered spam due to the fact that invisible (meta)data inevitably ends up being abused. Avoid invisible (meta)data. Publish visible data.

			== abbrとtitleに関するデザインパターン ==
			===''Q. Why is ABBR being used when the title attribute is available on all HTML elements?''===

			In the datetime design pattern the title attribute is used for the value of the property and the node value is used as the display value. <abbr title="value-here">Display-Here</abbr>.

			A. The short answer is that <abbr> has the correct semantics.

			The longer answer is that the value is often an abbreviated version of the formal value. Of course, if you don't want to use an <abbr>, you can use another element like this:

			<abbr title="2006-12-31T12:59:59Z" class="dtstamp">New Year</abbr>

			<span class="dtstamp">2006-12-31T12:59:59Z</span>

			In addition, microformats encourage the content to be visible and thus prefer the text of an element rather than using the 'title' attribute or any other less visible alternative. The exception is made for datetimes and abbr due to the fact that microformats are for humans first, machines second. Thus the content of the abbr element is used to provide human visible content and the machine equivalent is placed in the less visible (but still easily verifiable) 'title' attribute.

			== 要素の入れ子 ==
			===''Q. <code><span class="vcard fn org" id="club">...</span></code>としたいのですが、良いのでしょうか?''===

			A. ダメです。[[hcard-faq#nesting-properties]]を見てください。

ZbzYc4 at 13:08, 13 June 2007

2007-06-13T13:08:56Z

← Older revision		Revision as of 13:08, 13 June 2007
Line 158:		Line 158:


	== <code>~~<div></code>と<code><span></code>のセマンティクス ==~~		== <code>

	~~===''Q. Is it semantically meaningless to use divs?'' ===~~

	A. Yes, both <code><div></code> and <code><span></code> have nearly no semantics. <code><div></code> can be used to represent a "division" of the page content. Similarly <code><span></code> can be used to reperesent that that "span" of text has some meaning, but the specifics of what that meaning is undefined by the <code><span></code>.


	~~===''Q. Does the use of <code><div></code> and <code><span></code> elements add any semantics to web pages?''===~~

	A. According to the [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.4 HTML 4 spec], <code><div></code> and <code><span></code> "offer a generic mechanism for adding structure to documents." Their only meaning is in dividing documents into sections, and as such, their presence implies that the content within has a specific, but undefined by the element markup, semantic. Thus they are nearly semantic-free.


	~~===''Q. Why do the examples on the wiki use <code class="element"><span></code> and <code class="element"><div></code> for nearly everything?''===~~

	A. <code class="element"><span></code> and <code class="element"><div></code> are generic elements in HTML. When you use microformats, you should pick the most specific semantic element available for the semantics you are trying to express. You might, for example, apply <code>class="vevent"</code> to a <code><nowiki><tr></nowiki></code>, or <code>class="vcard"</code> to a <code><nowiki><p></nowiki></code>.

	~~== classのセマンティクス ==~~

	~~===Q. ''How will microformat class names impact page size?''===~~

	A. You probably won't notice any impact on page size when authoring with microformats. Our experience is that people use comparably sized class names, and [[semantic-class-names\|semantic class names]] are now considered an industry best practice. Some sites are successfully publishing millions of microformats, and we haven't heard any complaints yet. You are more likely to gain space savings by more fully adopting [[microformats#the_microformats_principles\|the principles of microformats]], and eliminating tables for layout.
	~~<span class="todo">''TODO: Consider creating a new section for web authoring tips? Or at least linking to another site that advocates good authorship.''</span>~~

	~~===Q. ''1つの要素に複数のclass名を付けることはできますか?''===~~

	~~A. できます。class属性の値は、空白区切りを入れることで複数のclass名を書くことができます。例えば次のようになります。~~
	~~<p class="todo idea">Write high quality and simple mark-up.</p>~~

	~~W3C HTML 4.01 Specificationのclass属性についての記述も見てください: [http://www.w3.org/TR/html401/struct/global.html#adef-class 7.5.2 Element identifiers: the id and class attributes]~~

	~~===Q. ''Do (X)HTML class names have semantics?''===~~

	A. The HTML4 specification does not define any particular class values [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF], nor does it define any particular semantic for class values [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF], except that they "may be used for general user agent processing" [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF]. However, the [http://www.w3.org/TR/WD-htmllink-970328#profile" draft of "Hypertext Links in HTML"], allows for a "profile" to define meanings for those classes. [http://gmpg.org/xmdp/ XMDP] is a format for defining meta data profiles for (X)HTML, and thus an XMDP profile can be used to define the meanings of class names.

	~~See also:~~
	* [http://tantek.com/log/2002/12.html#L20021216 A Touch Of Class]
	* [http://www.w3.org/TR/WD-htmllink-970328 Hypertext Links in HTML]

	~~===Q. ''I thought one of the main goals of CSS was to separate data from presentation. Isn’t this sneaking presentation back into data?''===~~

	A. This is a quite commonly expressed objection to the way microformats uses class, but it's based on a misunderstanding of the way the class attribute in HTML was designed. Yes, class is very commonly,and appropriately used by web designers in conjunction with CSS to style pages, and in truth, it is often overused for that, but despite this, class, according to the HTML specification "has several roles in HTML", including [http://www.w3.org/TR/html4/struct/global.html#h-7.5.2 "for general purpose processing by user agents"].

	Microformats utilize this second aspect of the class (and id) attribute, and do so legitimately. It is not an abuse of the class or id attribute to use it to add semantic context to a document. Nor is the use of class in and of itself presentational - in fact, it is an important mechanism for separating presentation from structured content.

	~~For some more on using class semantically, here are some articles~~

	* [http://meyerweb.com/eric/thoughts/2004/07/18/competent-classing Competent Classing by Eric Meyer]
	* [http://www.w3.org/QA/Tips/goodclassnames Use class with semantics in mind, W3C]
	* [http://tantek.com/log/2004/07.html#d20t2359 More about the class attribute, Tantek Çelik]

	~~== microformatsとspam ==~~
	~~===''Q. Given that Google now looks at hidden content as potential spam, will invisible microformats be considered spam?''===~~

	A. It is advisable not to hide information in your site, regardless of whether it is microformated or not. Microformats provide a mechanism for marking up ''visible'' content. Any mechanism for embedding ''invisible'' or hidden content risks being considered spam due to the fact that invisible (meta)data inevitably ends up being abused. Avoid invisible (meta)data. Publish visible data.

	~~== abbrとtitleに関するデザインパターン ==~~
	~~===''Q. Why is ABBR being used when the title attribute is available on all HTML elements?''===~~

	~~In the datetime design pattern the title attribute is used for the value of the property and the node value is used as the display value. <abbr title="value-here">Display-Here</abbr>.~~

	~~A. The short answer is that <abbr> has the correct semantics.~~

	~~The longer answer is that the value is often an abbreviated version of the formal value. Of course, if you don't want to use an <abbr>, you can use another element like this:~~

	~~<abbr title="2006-12-31T12:59:59Z" class="dtstamp">New Year</abbr>~~

	~~<span class="dtstamp">2006-12-31T12:59:59Z</span>~~

	In addition, microformats encourage the content to be visible and thus prefer the text of an element rather than using the 'title' attribute or any other less visible alternative. The exception is made for datetimes and abbr due to the fact that microformats are for humans first, machines second. Thus the content of the abbr element is used to provide human visible content and the machine equivalent is placed in the less visible (but still easily verifiable) 'title' attribute.

	~~== 要素の入れ子 ==~~
	~~===''Q. <code><span class="vcard fn org" id="club">...</span></code>としたいのですが、良いのでしょうか?''===~~

	~~A. ダメです。[[hcard-faq#nesting-properties]]を見てください。~~

RyanKing: Reverted edit of BxrT23, changed back to last version by IwaiMasaharu

2007-04-11T17:08:21Z

Reverted edit of BxrT23, changed back to last version by IwaiMasaharu

← Older revision		Revision as of 17:08, 11 April 2007
Line 158:		Line 158:


	== <code>		== <code><div></code>と<code><span></code>のセマンティクス ==

			===''Q. Is it semantically meaningless to use divs?'' ===

			A. Yes, both <code><div></code> and <code><span></code> have nearly no semantics. <code><div></code> can be used to represent a "division" of the page content. Similarly <code><span></code> can be used to reperesent that that "span" of text has some meaning, but the specifics of what that meaning is undefined by the <code><span></code>.


			===''Q. Does the use of <code><div></code> and <code><span></code> elements add any semantics to web pages?''===

			A. According to the [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.4 HTML 4 spec], <code><div></code> and <code><span></code> "offer a generic mechanism for adding structure to documents." Their only meaning is in dividing documents into sections, and as such, their presence implies that the content within has a specific, but undefined by the element markup, semantic. Thus they are nearly semantic-free.


			===''Q. Why do the examples on the wiki use <code class="element"><span></code> and <code class="element"><div></code> for nearly everything?''===

			A. <code class="element"><span></code> and <code class="element"><div></code> are generic elements in HTML. When you use microformats, you should pick the most specific semantic element available for the semantics you are trying to express. You might, for example, apply <code>class="vevent"</code> to a <code><nowiki><tr></nowiki></code>, or <code>class="vcard"</code> to a <code><nowiki><p></nowiki></code>.

			== classのセマンティクス ==

			===Q. ''How will microformat class names impact page size?''===

			A. You probably won't notice any impact on page size when authoring with microformats. Our experience is that people use comparably sized class names, and [[semantic-class-names\|semantic class names]] are now considered an industry best practice. Some sites are successfully publishing millions of microformats, and we haven't heard any complaints yet. You are more likely to gain space savings by more fully adopting [[microformats#the_microformats_principles\|the principles of microformats]], and eliminating tables for layout.
			<span class="todo">''TODO: Consider creating a new section for web authoring tips? Or at least linking to another site that advocates good authorship.''</span>

			===Q. ''1つの要素に複数のclass名を付けることはできますか?''===

			A. できます。class属性の値は、空白区切りを入れることで複数のclass名を書くことができます。例えば次のようになります。
			<p class="todo idea">Write high quality and simple mark-up.</p>

			W3C HTML 4.01 Specificationのclass属性についての記述も見てください: [http://www.w3.org/TR/html401/struct/global.html#adef-class 7.5.2 Element identifiers: the id and class attributes]

			===Q. ''Do (X)HTML class names have semantics?''===

			A. The HTML4 specification does not define any particular class values [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF], nor does it define any particular semantic for class values [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF], except that they "may be used for general user agent processing" [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF]. However, the [http://www.w3.org/TR/WD-htmllink-970328#profile" draft of "Hypertext Links in HTML"], allows for a "profile" to define meanings for those classes. [http://gmpg.org/xmdp/ XMDP] is a format for defining meta data profiles for (X)HTML, and thus an XMDP profile can be used to define the meanings of class names.

			See also:
			* [http://tantek.com/log/2002/12.html#L20021216 A Touch Of Class]
			* [http://www.w3.org/TR/WD-htmllink-970328 Hypertext Links in HTML]

			===Q. ''I thought one of the main goals of CSS was to separate data from presentation. Isn’t this sneaking presentation back into data?''===

			A. This is a quite commonly expressed objection to the way microformats uses class, but it's based on a misunderstanding of the way the class attribute in HTML was designed. Yes, class is very commonly,and appropriately used by web designers in conjunction with CSS to style pages, and in truth, it is often overused for that, but despite this, class, according to the HTML specification "has several roles in HTML", including [http://www.w3.org/TR/html4/struct/global.html#h-7.5.2 "for general purpose processing by user agents"].

			Microformats utilize this second aspect of the class (and id) attribute, and do so legitimately. It is not an abuse of the class or id attribute to use it to add semantic context to a document. Nor is the use of class in and of itself presentational - in fact, it is an important mechanism for separating presentation from structured content.

			For some more on using class semantically, here are some articles

			* [http://meyerweb.com/eric/thoughts/2004/07/18/competent-classing Competent Classing by Eric Meyer]
			* [http://www.w3.org/QA/Tips/goodclassnames Use class with semantics in mind, W3C]
			* [http://tantek.com/log/2004/07.html#d20t2359 More about the class attribute, Tantek Çelik]

			== microformatsとspam ==
			===''Q. Given that Google now looks at hidden content as potential spam, will invisible microformats be considered spam?''===

			A. It is advisable not to hide information in your site, regardless of whether it is microformated or not. Microformats provide a mechanism for marking up ''visible'' content. Any mechanism for embedding ''invisible'' or hidden content risks being considered spam due to the fact that invisible (meta)data inevitably ends up being abused. Avoid invisible (meta)data. Publish visible data.

			== abbrとtitleに関するデザインパターン ==
			===''Q. Why is ABBR being used when the title attribute is available on all HTML elements?''===

			In the datetime design pattern the title attribute is used for the value of the property and the node value is used as the display value. <abbr title="value-here">Display-Here</abbr>.

			A. The short answer is that <abbr> has the correct semantics.

			The longer answer is that the value is often an abbreviated version of the formal value. Of course, if you don't want to use an <abbr>, you can use another element like this:

			<abbr title="2006-12-31T12:59:59Z" class="dtstamp">New Year</abbr>

			<span class="dtstamp">2006-12-31T12:59:59Z</span>

			In addition, microformats encourage the content to be visible and thus prefer the text of an element rather than using the 'title' attribute or any other less visible alternative. The exception is made for datetimes and abbr due to the fact that microformats are for humans first, machines second. Thus the content of the abbr element is used to provide human visible content and the machine equivalent is placed in the less visible (but still easily verifiable) 'title' attribute.

			== 要素の入れ子 ==
			===''Q. <code><span class="vcard fn org" id="club">...</span></code>としたいのですが、良いのでしょうか?''===

			A. ダメです。[[hcard-faq#nesting-properties]]を見てください。

BxrT23 at 16:32, 11 April 2007

2007-04-11T16:32:05Z

← Older revision		Revision as of 16:32, 11 April 2007
Line 158:		Line 158:


	== <code>~~<div></code>と<code><span></code>のセマンティクス ==~~		== <code>

	~~===''Q. Is it semantically meaningless to use divs?'' ===~~

	A. Yes, both <code><div></code> and <code><span></code> have nearly no semantics. <code><div></code> can be used to represent a "division" of the page content. Similarly <code><span></code> can be used to reperesent that that "span" of text has some meaning, but the specifics of what that meaning is undefined by the <code><span></code>.


	~~===''Q. Does the use of <code><div></code> and <code><span></code> elements add any semantics to web pages?''===~~

	A. According to the [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.4 HTML 4 spec], <code><div></code> and <code><span></code> "offer a generic mechanism for adding structure to documents." Their only meaning is in dividing documents into sections, and as such, their presence implies that the content within has a specific, but undefined by the element markup, semantic. Thus they are nearly semantic-free.


	~~===''Q. Why do the examples on the wiki use <code class="element"><span></code> and <code class="element"><div></code> for nearly everything?''===~~

	A. <code class="element"><span></code> and <code class="element"><div></code> are generic elements in HTML. When you use microformats, you should pick the most specific semantic element available for the semantics you are trying to express. You might, for example, apply <code>class="vevent"</code> to a <code><nowiki><tr></nowiki></code>, or <code>class="vcard"</code> to a <code><nowiki><p></nowiki></code>.

	~~== classのセマンティクス ==~~

	~~===Q. ''How will microformat class names impact page size?''===~~

	A. You probably won't notice any impact on page size when authoring with microformats. Our experience is that people use comparably sized class names, and [[semantic-class-names\|semantic class names]] are now considered an industry best practice. Some sites are successfully publishing millions of microformats, and we haven't heard any complaints yet. You are more likely to gain space savings by more fully adopting [[microformats#the_microformats_principles\|the principles of microformats]], and eliminating tables for layout.
	~~<span class="todo">''TODO: Consider creating a new section for web authoring tips? Or at least linking to another site that advocates good authorship.''</span>~~

	~~===Q. ''1つの要素に複数のclass名を付けることはできますか?''===~~

	~~A. できます。class属性の値は、空白区切りを入れることで複数のclass名を書くことができます。例えば次のようになります。~~
	~~<p class="todo idea">Write high quality and simple mark-up.</p>~~

	~~W3C HTML 4.01 Specificationのclass属性についての記述も見てください: [http://www.w3.org/TR/html401/struct/global.html#adef-class 7.5.2 Element identifiers: the id and class attributes]~~

	~~===Q. ''Do (X)HTML class names have semantics?''===~~

	A. The HTML4 specification does not define any particular class values [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF], nor does it define any particular semantic for class values [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF], except that they "may be used for general user agent processing" [http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2 REF]. However, the [http://www.w3.org/TR/WD-htmllink-970328#profile" draft of "Hypertext Links in HTML"], allows for a "profile" to define meanings for those classes. [http://gmpg.org/xmdp/ XMDP] is a format for defining meta data profiles for (X)HTML, and thus an XMDP profile can be used to define the meanings of class names.

	~~See also:~~
	* [http://tantek.com/log/2002/12.html#L20021216 A Touch Of Class]
	* [http://www.w3.org/TR/WD-htmllink-970328 Hypertext Links in HTML]

	~~===Q. ''I thought one of the main goals of CSS was to separate data from presentation. Isn’t this sneaking presentation back into data?''===~~

	A. This is a quite commonly expressed objection to the way microformats uses class, but it's based on a misunderstanding of the way the class attribute in HTML was designed. Yes, class is very commonly,and appropriately used by web designers in conjunction with CSS to style pages, and in truth, it is often overused for that, but despite this, class, according to the HTML specification "has several roles in HTML", including [http://www.w3.org/TR/html4/struct/global.html#h-7.5.2 "for general purpose processing by user agents"].

	Microformats utilize this second aspect of the class (and id) attribute, and do so legitimately. It is not an abuse of the class or id attribute to use it to add semantic context to a document. Nor is the use of class in and of itself presentational - in fact, it is an important mechanism for separating presentation from structured content.

	~~For some more on using class semantically, here are some articles~~

	* [http://meyerweb.com/eric/thoughts/2004/07/18/competent-classing Competent Classing by Eric Meyer]
	* [http://www.w3.org/QA/Tips/goodclassnames Use class with semantics in mind, W3C]
	* [http://tantek.com/log/2004/07.html#d20t2359 More about the class attribute, Tantek Çelik]

	~~== microformatsとspam ==~~
	~~===''Q. Given that Google now looks at hidden content as potential spam, will invisible microformats be considered spam?''===~~

	A. It is advisable not to hide information in your site, regardless of whether it is microformated or not. Microformats provide a mechanism for marking up ''visible'' content. Any mechanism for embedding ''invisible'' or hidden content risks being considered spam due to the fact that invisible (meta)data inevitably ends up being abused. Avoid invisible (meta)data. Publish visible data.

	~~== abbrとtitleに関するデザインパターン ==~~
	~~===''Q. Why is ABBR being used when the title attribute is available on all HTML elements?''===~~

	~~In the datetime design pattern the title attribute is used for the value of the property and the node value is used as the display value. <abbr title="value-here">Display-Here</abbr>.~~

	~~A. The short answer is that <abbr> has the correct semantics.~~

	~~The longer answer is that the value is often an abbreviated version of the formal value. Of course, if you don't want to use an <abbr>, you can use another element like this:~~

	~~<abbr title="2006-12-31T12:59:59Z" class="dtstamp">New Year</abbr>~~

	~~<span class="dtstamp">2006-12-31T12:59:59Z</span>~~

	In addition, microformats encourage the content to be visible and thus prefer the text of an element rather than using the 'title' attribute or any other less visible alternative. The exception is made for datetimes and abbr due to the fact that microformats are for humans first, machines second. Thus the content of the abbr element is used to provide human visible content and the machine equivalent is placed in the less visible (but still easily verifiable) 'title' attribute.

	~~== 要素の入れ子 ==~~
	~~===''Q. <code><span class="vcard fn org" id="club">...</span></code>としたいのですが、良いのでしょうか?''===~~

	~~A. ダメです。[[hcard-faq#nesting-properties]]を見てください。~~