--- a/extensions/kwarchive.py	Thu Aug 16 23:37:20 2018 +0200
+++ b/extensions/kwarchive.py	Thu Aug 16 23:43:16 2018 +0200
@@ -18,11 +18,15 @@
 Example::
 
    [patterns]
+    #
     # expand keywords in every python file except those matching "x*"
+    # using RCS style expansion format (which is the default style)
     **.py =
     x*    = NO
-    # this file has reStructuredText style keyword expansion "|VCS<kw>|"
+    # this file has reStructuredText style keyword expansion "|VCS<kw>|" only
     path:VERSION = reST
+    # this file has reStructuredText style and RCS style keyword expansion
+    path:README = reST, RCS
 
 A non-existing ``.hgkwarchive`` file deactivates keyword expansion as does
 an empty ``[patterns]`` section.
@@ -323,6 +327,7 @@
         include = []
         exclude = []
         patterns = []
+        patterns_rcs = []
         patterns_rst = []
         if cfg.items("patterns"):
             for pattern, styles in cfg.items("patterns"):
@@ -333,12 +338,29 @@
                     exclude.append(pattern)
                 else:
                     patterns.append(pattern)
-                if "REST" in styles or "RST" in styles:
-                    patterns_rst.append(pattern)
+                if "REST" in styles or "RST" in styles \
+                        or "RCS" in styles:
+                    if "RCS" in styles:
+                        patterns_rcs.append(pattern)
+                    if "REST" in styles or "RST" in styles:
+                        patterns_rst.append(pattern)
+                else:
+                    # default to RCS if no keyword style is given
+                    patterns_rcs.append(pattern)
             matcher = match.match(repo.root, '', patterns=patterns,
                                   include=include, exclude=exclude)
         else:
             matcher = match.never(repo.root, '')
+
+        #
+        # An empty patterns_rcs does not mean that match_rcs is always
+        # true.
+        #
+        if not patterns_rcs:
+            matcher_rcs = match.never(repo.root, '')
+        else:
+            matcher_rcs = match.match(repo.root, '', patterns=patterns_rcs,
+                                      include=[], exclude=[])
         #
         # An empty patterns_rst does not mean that match_rst is always
         # true.
@@ -372,13 +394,14 @@
             _MARKER = '$'
             _MARKER_RST = '|'
             for kw, value in itertools.chain(keywords.items(), file_keywords.items()):
+                if matcher_rcs(real_name):
+                    filekw = "%s%s%s" % (_MARKER, kw, _MARKER)
+                    filevalue = "%s%s: %s %s" % (_MARKER, kw, value, _MARKER)
+                    data = data.replace(filekw, filevalue)
                 if matcher_rst(real_name):
                     filekw = "%sVCS%s%s" % (_MARKER_RST, kw, _MARKER_RST)
                     filevalue = value
-                else:
-                    filekw = "%s%s%s" % (_MARKER, kw, _MARKER)
-                    filevalue = "%s%s: %s %s" % (_MARKER, kw, value, _MARKER)
-                data = data.replace(filekw, filevalue)
+                    data = data.replace(filekw, filevalue)
             return data
 
     return _filter