12.3.1.1 index.???

index.name is the name of the index section. This string is used in \Wbegin to initialize the TeX macro \INDEX. The index section is recognized by matching, for a starred section, the actual section name against the contents of \INDEX. When they match, a new page and two-column mode are begun. These rules imply that the last section of one’s source file can be titled ‘\INDEX’, as in

@* \INDEX.

index.tex is the name of the file into which the Index is written. The character ‘#’ is translated into the root name of the web file, as for example ‘#.ndx’.

index.preamble are TeX commands that begin the Index.

index.postamble are TeX commands that end the Index.

index.collate specifies the collating sequence for the Index.