TFM files provide "TEX Font Metric" information for typesetting. Fonts
can be printed on the Dover and Canon only if (and usually if) there exists
a file of the form *.tfm[tex,sys]. Font names longer than six characters
are truncated by retaining the first and last three (e.g., "helica" for
helvetica, "helcab" for helvetica bold, "oldish" for Old English).
Read TFM.TXT[tex,sys] for more details.