Where do you want that documented? Inside macros.tex, or in a separate file?

WIP:

• techterm -- used (inconsistently) in the library to introduce (and sometimes incorrectly to refer to) a technical term, e.g. "An \techterm{invalid} iterator is ..."
• defnx -- used to introduce/define a technical term (so same as techterm?), adding an index entry for the second argument, e.g. "the \defnx{observable behavior}{behavior!observable} of the program"
• defn -- Same as \defn, reusing the same text for the term and the index entry.
• term -- similar to defn, but without an index entry (so maybe defn should be defined using term, not using textit directly).
• grammarterm -- used in text/examples when referring to a grammar production from the formal C++ grammar, e.g. "the potential scope of the \grammarterm{using-directive} that follows"
• placeholder -- a placeholder variable/type such as "Let i be ...", formatted in italics (or maybe math font, see issue placeholders should be formatted with math fonts #326)

WIP:

Use \bigoh for Big-O complexity requirements, e.g. \bigoh{log(N)}

Use \Cpp for "C++" (it has special rules to make it look nicer).

Use \range for a half-open range, e.g. \range{0}{N} => [0, N), and similarly \orange, \crange and \brange for open ranges, closed ranges, and "backwards" half-open (e.g. (first,last], as used for copy_backward) ranges, respectively.