\
tenrm
LaTeX 2.09 defined a large set of commands for access to the fonts
that it had built in to itself. For example, various flavours of
cmr
could be found as \
fivrm
, \
sixrm
, \
sevrm
,
\
egtrm
, \
ninrm
, \
tenrm
, \
elvrm
, \
twlrm
,
\
frtnrm
, \
svtnrm
, \
twtyrm
and \
twfvrm
.
These commands were never documented, but certain packages
nevertheless used them to achieve effects they needed.
Since the commands weren't public, they weren't included in LaTeX2e; to use the unconverted LaTeX 2.09 packages under LaTeX2e, you need also to include the rawfonts package (which is part of the LaTeX2e distribution).
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=oldfontnames