geom style
requires NFSS,
a rational font management system that makes the use of new
fonts easier than under traditional .
Under this scheme, unlike the old, if you say \bf... \small...,
the \small has no effect on the boldness of the current
font—size, boldness, style and so on are independent attributes.
This is generally good, but it does create backward incompatibilities.
For example, if you have an old document where you've relied
on \small to reset the weight of the font, you're in for a
surprise. Also, \rm should generally be replaced by
\normalshape. For a list of all such differences, see
[#!amslatex!#].
Another case of conflicting ideas on what font-change commands should
do is inside math mode. Under NFSS,
\bf has no effect inside math mode—you need to say
$\bold{xyz}$, for example. The geom style will
print a warning on your terminal if it sees \bf in math mode.
In addition to the math-mode commands \bold, \mathrm and
\mathit, the geom style defines \sans and
\type as the math mode counterparts of \sf (sans-serif)
and \tt (typewriter type).
Support for Fraktur (``gothic'') and blackboard-bold fonts is
provided, as well as for the fonts msam and msbm, which
contain a plethora of mathematical symbols. This is all thanks to the
AMS, and you should turn to the / distribution
[#!amslatex!#] if your site lacks the fonts themselves or the
prerequisite auxiliary files amsfonts.sty and
amssymb.sty.