General Commands Manual
NAME test — condition evaluation utility
The standard way to escape a delimiter in a macro argument is to prepend a zero-width space, like this:
The -? option displays a summary of the commands.
Appending the zero-width space or enclosing the delimiter in double quotes works too, but isn't recommended because these methods are less commonly used:
If escaping is forgotten, delimiters fall out of the macros. If that leaves the macros empty, they may assume their default arguments. For example,
.Nm [ Ar expression Cm ]
[test expression ]
where the square brackets are not set in bold face.