When using many Emacs’ help commands (like C-h f, or describe-function), we are presented with the *Help* buffer. It has some basic navigation commands, most importantly forward-button (TAB), hepl-follow (RET), help-go-back (l) and help-go-forward (r), and usually they are enough for me.
Some time ago, however, I had a very specific need which could not be achieved by any of them. I wanted to compare the docstrings of two similar functions. Here’s the issue – calling describe-function replaces the contents of the *Help* buffer with the docstring of the next one. I could press l and r repeatedly, of course, but I really wanted to see both docstrings at the same time.
Well, I did the first thing that came to my mind, and it just worked. I switched to the *Help* buffer, said M-x rename buffer *Help 2* RET and called describe-function again. Precisely as expected, I ended up with two help buffers. One drawback was that the “second” one did not have the help history (for some reason), but that didn’t bother me much – after I compared the docstrings I just killed it and that’s it.
This is definitely not the sort of the tip you’d need every day, but it might be helpful one day, so I decided to share it. Happy Emacs-ing!