Index: Mk/Uses/shebangfix.mk
===================================================================
--- Mk/Uses/shebangfix.mk
+++ Mk/Uses/shebangfix.mk
@@ -13,6 +13,11 @@
 #
 #   SHEBANG_FILES=	path1/file path2/*.pl
 #
+# To define custom shebangs to replace, use the following (note that
+# shebangs with spaces should be quoted):
+#
+#   perl_OLD_CMD=	/usr/bin/perl5.005 "/usr/bin/setenv perl5.005"
+#
 # To define a new shebang scheme add the following to the port Makefile:
 #
 #   SHEBANG_LANG=	lua