diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -35,6 +35,7 @@ from . import (
     hg,
     hook,
     revset,
+    templatekw,
     ui as uimod,
     util,
 )
@@ -758,6 +759,7 @@ extraloaders = [
     ('cmdtable', commands, 'loadcmdtable'),
     ('filesetpredicate', fileset, 'loadpredicate'),
     ('revsetpredicate', revset, 'loadpredicate'),
+    ('templatekeyword', templatekw, 'loadkeyword'),
 ]
 
 def _dispatch(req):
diff --git a/mercurial/registrar.py b/mercurial/registrar.py
--- a/mercurial/registrar.py
+++ b/mercurial/registrar.py
@@ -161,3 +161,33 @@ class filesetpredicate(_funcregistrarbas
     def _extrasetup(self, name, func, callstatus=False, callexisting=False):
         func._callstatus = callstatus
         func._callexisting = callexisting
+
+class _templateregistrarbase(_funcregistrarbase):
+    """Base of decorator to register functions as template specific one
+    """
+    _docformat = ":%s: %s"
+
+class templatekeyword(_templateregistrarbase):
+    """Decorator to register template keyword
+
+    Usage::
+
+        templaetkeyword = registrar.templatekeyword()
+
+        @templatekeyword('mykeyword')
+        def mykeywordfunc(repo, ctx, templ, cache, revcache, **args):
+            '''Explanation of this template keyword ....
+            '''
+            pass
+
+    The first string argument is used also in online help.
+
+    'templatekeyword' instance in example above can be used to
+    decorate multiple functions.
+
+    Decorated functions are registered automatically at loading
+    extension, if an instance named as 'templatekeyword' is used for
+    decorating in extension.
+
+    Otherwise, explicit 'templatekw.loadkeyword()' is needed.
+    """
diff --git a/mercurial/templatekw.py b/mercurial/templatekw.py
--- a/mercurial/templatekw.py
+++ b/mercurial/templatekw.py
@@ -574,5 +574,11 @@ keywords = {
     'tags': showtags,
 }
 
+def loadkeyword(ui, extname, registrarobj):
+    """Load template keyword from specified registrarobj
+    """
+    for name, func in registrarobj._table.iteritems():
+        keywords[name] = func
+
 # tell hggettext to extract docstrings from these functions:
 i18nfunctions = keywords.values()