[pdftex] lettering (not numbering) chapters

[William Adams]

I've just finished whacking at this at work---my solution was to number
them in hexadecimal (fortunately there're only four of them, and
fortuituously 10 was the last numbered chapter...).

If you're using LaTeX, you should be able to just issue \appendix or
some such to change over though. I know the memoir class defines
``\backmatter'' which properly addresses this.

William