-override wrapplaintext = $(PRINTF) '%s\n' "$$($(PRINTF) '%b' '<?xml version=\042\061.0\042?>\n<script xmlns=\042http://www.w3.org/1999/xhtml\042 type=\042$(call typeoffile,$1)\042><![CDATA['; $(CAT) $(call quote,$1) | $(TR) '\000\013\014' '\032\011\012' | $(SED) $$($(PRINTF) '%s%b' 's/]]>/]]]]><!\[CDATA\[>/g;s/\xEF\xBF\xBE/�/g;s/\xEF\xBF\xBF/�/g;$$!s/\r$$//g;s/\r/\n/g;$$!s/\xC2\x85$$//g;s/\xC2\x85/\n/g;s/\xE2\x80\xA8/\n/g;' 's/[\0001-\0010]/�/g;s/[\0016-\0037]/�/g'); $(PRINTF) '%s' ']]></script>')"
+override wrapplaintext = $(TR) '\000\013\014' '\032\011\012' < $(call quote,$1) | $(SED) "$$($(PRINTF) '%b' 's/]]>/]]]]><!\\[CDATA\\[>/g\ns/\0357\0277\0276/�/g\ns/\0357\0277\0277/�/g\n$$!s/\\r$$//g\ns/\\r/\\n/g\n$$!s/\0302\0205$$//g\ns/\0302\0205/\\n/g;s/\0342\0200\0250/\\n/g;s/[\0001-\0010]/�/g;s/[\0016-\0037]/�/g')" | $(XARGS) -0 -J %% $(PRINTF) '%b%s%s\n' '<?xml version=\042\061.0\042?>\n<script xmlns=\042http://www.w3.org/1999/xhtml\042 type=\042$(call typeoffile,$1)\042><![CDATA[' %% ']]></script>'
+
+# (callable) Check if the provided X·M·L file is X·M·L 1.1, and if so, coerce to X·M·L 1.0 as best as possible, printing the result (or the original file contents) to `stdout´.
+#
+# The X·M·L declaration will be dropped and character escapes for C0 control codes will be replaced with a literal `U+0091 PRIVATE USE ONE´, which is invalid in X·M·L 1.1, but valid X·M·L 1.0 (making the replacement obvious).
+#
+# This isn’t a perfect substitution (it makes some assumptions about the format of the underlying X·M·L), but it should be workable for most sensible, welformed files.
+override serializexml = $(SED) "$$($(PRINTF) '%b' '/<?xml[ \t]\\{1,\\}version=[\0042\0047]1.1/,$${ s/<?xml[^>]*?>/<!--<?xml version=\00421.1\0042?>-->/\n s/&\0043x0*[1-8BCEFbcef];/\0302\0221/g\n s/&\0043x0*1[0-9A-Fa-f];/\0302\0221/g\n s/&\00430*[1-8];/\0302\0221/g\n s/&\00430*1[124-9];/\0302\0221/g\n s/&\00430*2[0-9];/\0302\0221/g\n s/&\00430*3[01];/\0302\0221/g\n}')" < $(call quote,$1) | $(SED) "$$(PRINTF '%b' ':a\n/^\\n*$$/{ $$d\n N\n ba\n}')"