+However, if you really only want to replace the line for the default proxy,
+i.e. the one without a "for ..." postfix, do something like this:
+
+------------
+% git config-set proxy.command ssh '! for '
+------------
+
+To actually match only values with an exclamation mark, you have to
+
+------------
+% git config-set section.key value '[!]'
+------------
+