+*%{*'HEADER'*}p*::
+
+ Expands into the HTTP response header named by 'HEADER'. If
+ the specified header does not exist in the request, *%p*
+ expands into a dash.
+
+*%{*'HEADER'*}P*::
+
+ Similar to *%p*, except that 'HEADER' is prepended with
+ `X-Ash-`, for simple convenience.
+