+@cindex @key{DEL} vs @key{BACKSPACE}
+@cindex @key{BACKSPACE} vs @key{DEL}
+@cindex usual erasure key
+
+ Every keyboard has a large key, a little ways above the @key{RET} or
+@key{ENTER} key, which you normally use outside Emacs to erase the
+last character that you typed. We call this key @dfn{the usual
+erasure key}. In Emacs, it is supposed to be equivalent to @key{DEL},
+and when Emacs is properly configured for your terminal, it translates
+that key into the character @key{DEL}.
+
+ When Emacs starts up on a graphical display, it determines
+automatically which key should be @key{DEL}. In some unusual cases
+Emacs gets the wrong information from the system. If the usual
+erasure key deletes forwards instead of backwards, that is probably
+what happened---Emacs ought to be treating the @key{DELETE} key as
+@key{DEL}, but it isn't.
+
+ On a graphical display, if the usual erasure key is labeled
+@key{BACKSPACE} and there is a @key{DELETE} key elsewhere, but the
+@key{DELETE} key deletes backward instead of forward, that too
+suggests Emacs got the wrong information---but in the opposite sense.
+It ought to be treating the @key{BACKSPACE} key as @key{DEL}, and
+treating @key{DELETE} differently, but it isn't.
+
+ On a text-only terminal, if you find the usual erasure key prompts
+for a Help command, like @kbd{Control-h}, instead of deleting a
+character, it means that key is actually sending the @key{BS}
+character. Emacs ought to be treating @key{BS} as @key{DEL}, but it
+isn't.
+
+ In all of those cases, the immediate remedy is the same: use the
+command @kbd{M-x normal-erase-is-backspace-mode}. This toggles
+between the two modes that Emacs supports for handling @key{DEL}, so
+if Emacs starts in the wrong mode, this should switch to the right
+mode. On a text-only terminal, if you want to ask for help when
+@key{BS} is treated as @key{DEL}, use @key{F1}; @kbd{C-?} may also
+work, if it sends character code 127.
+
+@findex normal-erase-is-backspace-mode
+ To fix the problem automatically for every Emacs session, you can
+put one of the following lines into your @file{.emacs} file
+(@pxref{Init File}). For the first case above, where @key{DELETE}
+deletes forwards instead of backwards, use this line to make
+@key{DELETE} act as @key{DEL} (resulting in behavior compatible
+with Emacs 20 and previous versions):
+
+@lisp
+(normal-erase-is-backspace-mode 0)
+@end lisp