describe-key-briefly

describe-key-briefly is an interactive compiled Lisp function in `help.el'.

It is bound to C-h c, <f1> c, <help> c.

(describe-key-briefly &optional KEY INSERT UNTRANSLATED)

Print the name of the function KEY invokes. KEY is a string.
If INSERT (the prefix arg) is non-nil, insert the message in the buffer.
If non-nil, UNTRANSLATED is a vector of the untranslated events.
It can also be a number in which case the untranslated events from
the last key hit are used.

If KEY is a menu item or a tool-bar button that is disabled, this command
temporarily enables it to allow getting help on disabled items and buttons.