lc Library of Congress Identifiers 2007-10-15 Library of Congress 101 Independence Ave, SE Washington, DC 20540 http://www.loc.gov Ray Denenberg rden@loc.gov 202-707-5795 An 'info' URI with namespace 'lc' takes the form: info:lc/<lc-info-subspace>/<subspace-specific-string> lc-info-subspace lc-info-subspace = ALPHA *( ALPHA / DIGIT ) i.e. alphanumeric with leading alphabetic character. Values of lc-info-subspace are assigned by the Library of Congress and registered at http://www.loc.gov/standards/uri/LcInfoURI.html. The Library of Congress will designate an authority for each value. subspace-specific-string subspace-specific-string = subspace-specific-component *("/" subspace-specific-component) subspace-specific-component subspace-specific-component = pchar *(pchar) pchar (etc.) pchar is as defined in RFC 3986, that is: pchar = unreserved / pct-encoded / sub-delims / ":" / "@" unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~" pct-encoded = "%" HEXDIG HEXDIG sub-delims = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "=" ALPHA, DIGIT, AND HEXDIG are as defined in RFC 2234: upper or lower case alphabetic (A-Z / a-z), decimal digit (0-9), and hexadecimal digit (DIGIT / "A" / "B" / "C" / "D" / "E" / "F") respectively. Percent Encoded Characters No characters in general needs to be percent encoded. http://www.loc.gov/standards/uri/LcInfoURI.html All identifiers in the info:lc namespace are case-sensitive. info:lc/xmlns/marcxchange-v1 info:lc/xmlns/rmd-v1 info:lc/xmlns/update-v1 info:lc/xmlns/mods-4.0 This info namespace will be used for various lc identifiers, where the identifier class is specified by the lc-info-subspace. Only one such subspace is defined initially, ‘xmlns’. xmlns identifiers are XML namespace URIs. For a discussion of why ‘info:’ (rather than for example ‘http:’) might be used for XML namespace URIs, see http://www.loc.gov/standards/uri/xml-namespaces.html No service mechanisms are at present defined. If any are defined in the future they will be described at http://www.loc.gov/standards/uri/LcInfoURI.html