Here is a list of the changes that occured in the style sheet
language.

Version 4.9.10
	* Enforced the rule that the last read is wining.  Before
	sequences are
	  "%%" Comment,
	  "%" Comment
	end sequence
	had %% checked first, and
	sequences are
	  "%" Comment
	end sequence
	sequences are
	  "%%" Comment,
	end sequence
	had %% checked first.
	Now, no matter if it comes from an ancestor, or a previous
	definition block, or it is after another in the same block,
	it is *always* the last one which wins.
	* Regex can be spread on several lines.  E.g. (from mail.ssh)
     /^\\(From: \\)/		# \1. The From
     /\\([[:blank:]]*\\)/	# \2. Some blanks
     /\\([^(]+(\\)/		# \3. The email
     /\\([^)]+\\)/		# \4. Name of the sender (between paren)
     /\\().*\n\\)/		# \5. End of line
	\1 Keyword_strong, \2 Plain, 
	\3 Label_strong, \4 (Label_strong + Tag2), \5 Label_strong)
	* Matching is now first on strings, then on regexp.  This makes
	  easier to handle exceptions in regex.  I noticed no difference
	  with the existing style sheets.
	* The "default" face is no longer Plain, but Invisible.
	  In pratice this means that
	  "Foo" Tag1
	  with former a2pses was "Foo" Plain + Tag1
	  and now it is          "Foo" Invisible + Tag1

Version 4.9.8
	* Special constructs in documentation:
	  - url(address)url(name)url (cf. claire.ssh)
	  - @example
            Blah
            @end example
	    For text that must not be justified (cf gnuc.ssh).
	  - @itemize
	    @item
            Blah
	    @item
            Blah 2
	    @end itemize
	    For enumerations (cf. claire.ssh).

Version 4.9.7
	* "alphabets are" can be used as a shortcut.
	* "ancestors are" to extend existing style sheets.
	* "comment is" is replaced by "documentation is",
	   which is more explicit.
	* "closers are" for closing alternatives of sequences.
	* "requires" to specify needed a2ps version.

Version 4.9.6
	* There can be several strings ("string1" "string2" ...)
	  in "comments are".  An end-of-line is inserted between
	  each one (string1\nstring2...").

Version 4.9.5
	* The name of the files *must* (please respect this)
	  be 8+3, with no special chars.  They *all* should
	  be lower case, alphanumerical.  Nothing more!
	  This is of course for portability issues.
	  *Note*  The name of the style is not related to this.
	  It can be anything you want.

Version 4.9.4
	* "version is" is new.
	* "written by" is new.