- CDATA an Internet media type (aka MIME content type, as per
- NAME a string which begins with a latter (A-Z or a-z) and may be followed by any number of letters, digits, hyphens (-), and periods (.).
- NAMES a whitespace-separated list of NAMEs.
- NUMBER a positive integer
- PCDATA parsed character data; text occurring in a context in which markup and entity references may occur. Compare this with CDATA