readline: difference between vi, vi-move, vi-command, vi-insert keymaps

Question

The readline(3) manpage lists these four (vi, vi-move, vi-command, vi-insert) as possible options for the keymap setting. I have tried setting these different options and they seem to have no effect beyond what set editing-mode vi does.

Probably the most succinct way to answer this question is to give an example of how changing keymap makes a difference.

Quote from the manpage:

keymap (emacs)
          Set the current readline keymap.  The set of legal keymap  names
          is  emacs,  emacs-standard, emacs-meta, emacs-ctlx, vi, vi-move,
          vi-command, and vi-insert.   vi  is  equivalent  to  vi-command;
          <<snip>>

Answer 1

They are the different keymaps inside vi mode. For example, my .inputrc sets keymap to bind keys in different modes. Excerpt:

# insert mode bindings
set keymap vi-insert
"\C-p": previous-history
"\C-n": next-history

# command mode bindings
set keymap vi-command
"|": beginning-of-line
"_": vi-first-print