-\newcommand{\definition}[1]{#1} % FIXME: add to glossary and/or index
-\newcommand{\cmd}[1]{\texttt{#1}} % FIXME: add to glossary and/or index
+\newcommand{\definition}[1]{\textit{#1}\index{#1}} % FIXME: add to glossary?
+\newcommand{\cmd}[1]{\texttt{#1}\index{#1}} % FIXME: add to glossary?
+\newcommand{\magicnumber}[1]{\texttt{#1}}
+
+% ignore output, but evaluate command with side-effects
+\newsavebox{\trashbox}
+\newcommand{\ignoreoutput}[1]{\setbox\trashbox\vbox{#1}}