* doc/emacs/search.texi (Basic Isearch): Index
'isearch-delete-char', its keybinding and the isearch "input
item" concept, and define the latter.
(Error in Isearch): Clarify the different uses of DEL and
C-M-w during isearch.
* lisp/isearch.el (isearch-delete-char): Correct its
documentation and link to the Info node '(emacs)Basic Isearch'
which explains less technically how this function works in
everyday usage.