Add a DSSSL stylsheet to enable more efficient spellchecking. This

stylesheet omits the contents of <filename>, <devicename>,
<programlisting>, and other tags that are likely to not contain real
English words.  The output of this stylesheet can then be checked with
'make spellcheck' with far fewer false positives.

share/mk/doc.docbook.mk

@@ -58,6 +58,12 @@
 #	CSS_SHEET	Full path to a CSS stylesheet suitable for DocBook.
 #			Default is ${DOC_PREFIX}/share/misc/docbook.css
 #
+#
+#	SPELLCHECK	Use the special spellcheck.dsl stylesheet to render
+#			HTML that is suitable for processing through a 
+#			spellchecker.  For example, PGP keys and filenames
+#			will be ommitted from this output.
+#
 # Print-output options :
 #
 #       NICE_HEADERS    If defined, customized chapter headers will be created
@@ -120,6 +126,10 @@ STYLESHEET_TYPE?=	dsssl
 OPENJADE=	yes
 .endif
 
+.if defined(SPELLCHECK)
+DSLHTML?= ${DOC_PREFIX}/share/sgml/spellcheck.dsl
+.endif
+
 .if defined(OPENJADE)
 JADE?=		${PREFIX}/bin/openjade
 JADECATALOG?=	${PREFIX}/share/sgml/openjade/catalog

share/sgml/spellcheck.dsl

@@ -0,0 +1,63 @@
+<!-- $FreeBSD$ -->
+
+<!--
+
+The current generation of open source SGML aware spellcheckers are
+insufficient for our needs.  They produce far too many false positives
+since they just ignore the tags themselves but still spellcheck the
+contents of all tags.  This stylesheet specifically omits the output
+of tags that may contain data that should not be spellchecked.  For
+example, the contents of <filename> tags should not be spellchecked.
+
+-->
+
+<!DOCTYPE style-sheet PUBLIC "-//James Clark//DTD DSSSL Style Sheet//EN" [
+<!ENTITY freebsd.dsl PUBLIC "-//FreeBSD//DOCUMENT DocBook Stylesheet//EN" CDATA DSSSL>
+<!ENTITY % output.print "IGNORE">
+<!ENTITY % output.html		"IGNORE">
+
+]>
+
+<style-sheet>
+  <style-specification use="docbook">
+    <style-specification-body>
+
+      <![ %output.html; [ 
+
+
+<!--
+	  (element programlisting
+	    (if (equal? (normalize "pgpfingerprint") (attribute-string "role"))
+		(empty-sosofo)
+		(if (equal? (normalize "pgpkey") (attribute-string "role"))
+		    (empty-sosofo)
+		    (next-match))))
+-->
+
+	  (element programlisting
+	    (empty-sosofo))
+
+	  (element screen
+	    (empty-sosofo))
+
+	  (element hostid
+	    (empty-sosofo))
+
+	  (element filename
+	    (empty-sosofo))
+
+	  (element devicename
+	    (empty-sosofo))
+
+	  (element otheraddr
+	    (empty-sosofo))
+
+	  (element command
+	    (empty-sosofo))
+
+      ]]>
+    </style-specification-body>
+  </style-specification>
+
+  <external-specification id="docbook" document="freebsd.dsl">
+</style-sheet>