These three commands specify font changes in the printed manual and
have no effect in the Info file. `@i' requests italic font (in some
versions of TeX, a slanted font is used), `@b' requests bold face,
and `@t' requests the fixed-width font used by `@kbd'. All three
commands apply to an argument that follows, surrounded by braces.
If possible, you should avoid using these three commands. If you
find a need to use one, it probably indicates a lack in the Texinfo
language.
Dan