DCMI Type Vocabulary
A general, cross-domain list of Dublin Core Metadata Initiative (DCMI) approved terms that may be used as values for the resource type element to identify the genre of a resource.
MIME Internet Media Types
Originally called MIME (Multipurpose Internet Mail Extensions) types. http://www.iana.org/assignments/media-types/
Specifies identifiers for media types for file formats on the Internet.
RFC 4646 Tags for Identifying Languages
Describes the structure, content, construction, and semantics of language tags for use, as well as how to register values for use in language tags and the creation of user-defined extensions for private interchange. This document, in combination with RFC 4647, replaces RFC 3066, which replaced RFC 1766. (RFC 1766 specifies a two letter code taken from ISO 639Codes for the representation of names of languages, followed optionally by a two letter country code taken from ISO 3166 - English country names and code elements.)
ISO 3166 - English country names and code elements
Provides a standard numeric and 2-letter and 3-letter alphabetic codes for countries or areas of special sovereignty. This standard family includes Part 1: Country Codes and Part 2: Country Subdivision Code.
ISO 639 Codes for the representation of names of languages
Provides two sets of language codes for the representation of names of languages.
Part 1: Alpha-2 code includes identifiers for major languages of the world for which specialized terminologies have been developed. (http://xml.coverpages.org/iso639a.html)
Part 2: Alpha-3 code (http://www.loc.gov/standards/iso639-2/php/English_list.php) contains identifiers for all of the languages represented in part 1 and includes additional languages that have significant bodies of literature. It also provides identifiers for groups of languages, such as language families. When taken together these indirectly cover most languages of the world.
W3C Date and Time Formats (W3C-DTF)
Provides encoding rules for dates and times. As a profile based on ISO 8601 Data elements and interchange formats -- Information interchange -- Representation of dates and times, it defines a restricted range of formats. It also expresses the year as four digits in all cases.