This page lists the allowed extension values for the class="" attribute in HTML5. You may add your own values to this list, which makes them legal HTML5 class names. We ask that you try to avoid redundancy; if someone has already defined a name that does roughly what you want, please reuse it.
|Keyword||Applicable elements||Brief description||Link to more details||Synonyms||Status|
|author||p, span||Indicates that the element contains details of the author of a neighbouring image.||none||Proposal|
|advert||Block-level elements||Indicates that the element contains advertisement.||none||Proposal|
|credit||p, span||Indicates that the element contains some sort of credit or acknowledgment. Such as service providers, hosting, and software used.||none||Proposal|
|ct||em||Indicates that the element represents a conformance term. The element must have a single text node which value is one of the key words defined by RFC 2119, lowercased. It is expected that this class will mainly be used in specifications.||none||rfc2119||Proposal|
|msonormal||All elements||A value used by Microsoft Office HTML output to mean nothing (literally).||none||Unendorsed|
|price||span||Indicates that the element represents a price. If there is a child element
|robots-nocontent||All elements||Indicates that the element contains no information relevant to search engines. Such as main navigation, advertisement, dynamic content that is useful only to users, and disclaimers and copyright statments.||Yahoo! Slurp allready support this class||Proposal|
For the "Status" section to be changed to "Accepted", the proposed keyword must have been through the Microformats process, and been approved by the Microformats community. If it fails to go through this process, it is "Unendorsed".
For more details, see the HTML5 specification.