GNU Emacs Lisp Reference Manual
23.1.4 Getting Help about a Major Mode
The describe-mode function is used to provide information
about major modes. It is normally called with C-h m. The
describe-mode function uses the value of major-mode,
which is why every major mode function needs to set the
major-mode variable.
- Command: describe-mode
- This function displays the documentation of the current major mode.
The describe-mode function calls the documentation
function using the value of major-mode as an argument. Thus, it
displays the documentation string of the major mode function.
(See section 24.2 Access to Documentation Strings.)
- Variable: major-mode
- This variable holds the symbol for the current buffer's major mode.
This symbol should have a function definition that is the command to
switch to that major mode. The
describe-mode function uses the
documentation string of the function as the documentation of the major
mode.