Those are tagged strings. (some usage info)
Some clarification on this though.
The datatype (not really a datatype because TorqueScript doesn't have hard defined datatypes) of 'whatever' in commandtoserver('whatever'); is a
tagged string.
But if your looking for more things that you can replace whatever with, you're looking for
function names that start with serverCmd, which you can find more by following a previous post or searching (ctrl f) for serverCmd in a list such as
this (it may be outdated though, I don't know)