This tag has a single attribute, namely 'the number of the next document-wide numeric identifier to be allocated of the form z123'. The NEXTID tag is designed for use by automatic hypertext editors, and is not intended for use by mere humans. People writing HTML should generally use mnemonic alphabetical identifiers.
The NEXTID element should be placed in the document HEAD.
Example of use:
<HEAD> <NEXTID N=z27> . . </HEAD>