The \maybebm and \maybeit macros can be used in math expressions to make the arguments typeset as bold or italic respectively if the surrounding context is appropriate. They are useful for writing user macros for use in general contexts.

\maybebm is especially appropriate when section titles contain math expressions, since the title will appear bold but the header and table of contents usually replicate the title in normal width. It uses the bm package to make things bold

\maybeit performs a similar role to \mathrm{} but the math expression will be italicised if the surrounding text is. \maybeitsubscript is provided to shift subscripts to the left if the expression is italicised.

The author is Andy Buckley.