Today I learned, Emacs version. More of a mini blog. Inspired by jbranchaud/til.

The last line of the documentation string can specify calling conventions different from the actual function arguments. Write text like this:

\(fn arglist)

following a blank line, at the beginning of the line, with no newline following it inside the documentation string. (The ‘\’ is used to avoid confusing the Emacs motion commands.) The calling convention specified in this way appears in help messages in place of the one derived from the actual arguments of the function.