The index tags serve for making a index of your document.
They are only useful if you want do do LaTeX mapping.
They only differ very slightly as mentioned in table
Index elements.
There are two ways to include indices into your document.
Look at both and decide.
Manually
Set the opts attribute of your document class to
contain the packages makeidx.
You do that by: <article opts="makeidx">.
Mark all the words you want to be in the index later
with a idx tag or cdx tag.
If the word you want to index to a location in your document
is not within the text you simply write it at the location you
want to index with the nidx tag.
Itīs like the normal idx only the tagged text will be silently
dropped in the normal document.
Process your file with makeindex
sgml2latex -m mydocument.sgml.
This will produce an additional mydocument.idx.
Process mydocument.idx with the makeindex
command like makeindex mydocument.idx.
This will produce an additional mydocument.ind.
To include the now generated index in your document
you process your document with
sgml2latex -o tex -m mydocument.sgml.
This results in output of mydocument.tex.
Edit mydocument.tex with the editor of your choice.
You look for the line \end{document} (should be somewhere
close to the end of the file) and insert the text
\printindex bevor this line.
Process the modified file with latex mydocument.tex.
This gives you the final mydocument.dvi wich aggain you might
process with dvips to generate a postscript document.