--- a/README.txt	Sat May 16 13:04:04 2026 +0200
+++ b/README.txt	Sat May 16 14:59:46 2026 +0200
@@ -9,7 +9,7 @@
              All rights reserved.
 :License:    BSD 3-Clause "New" or "Revised" License.
              See :ref:`LICENSE.txt <license>` for more details.
-:Revision:   |VCSHGrevision|
+:Revision:   |VCSRevision|
 
 
 "ConfigMix" is a library to help with the configuration of

--- a/docs/conf.py	Sat May 16 13:04:04 2026 +0200
+++ b/docs/conf.py	Sat May 16 14:59:46 2026 +0200
@@ -15,6 +15,7 @@
 import datetime
 import os
 import sys
+
 sys.path.insert(0, os.path.dirname(os.path.abspath('.')))
 
 import configmix
@@ -30,14 +31,49 @@
 copyright = u('2015–2023, Franz Glasner. All rights reserved')
 author = 'Franz Glasner'
 
-# The short X.Y version
-version = '.'.join(configmix.__version__.split('.')[:2])
+current_date = datetime.date.today().isoformat()
+
 # The full version, including alpha/beta/rc tags
 release = configmix.__version__
-release_date = today = configmix.__date__
+# The short X.Y version
+version = '.'.join(release.split('.')[:2])
+
+#
+# Optimistically assume that all keywords are expanded properly everywhere:
+# do not define special VCSxxx keyword below.
+#
+define_rest_keywords = False
 
-current_date = datetime.date.today().isoformat()
-
+release_date = today = configmix.__date__
+if (not release_date
+        or (release_date.startswith("|") and release_date.endswith("|"))):
+    # Above assumption is not true: "hg kwarchive" nay not have been called
+    release_date = today = "dev-%s" % (current_date,)
+    define_rest_keywords = True
+release_rev = configmix.__revision__
+if (not release_rev
+        or (release_rev.startswith("|") and release_rev.endswith("|"))):
+    #
+    # Above assumption is not true: "hg kwarchive" may not have been called.
+    # Try to determine from VCS.
+    #
+    import subprocess
+    try:
+        release_rev = subprocess.check_output(
+            ["hg", "id", "-i"], stderr=subprocess.STDOUT)
+    except Exception:
+        release_rev = "<UNKNOWN>"
+    else:
+        if sys.version_info[0] >= 3:
+            release_rev = release_rev.decode("ascii")
+        release_rev = "dev-%s" % (release_rev.strip(),)
+    define_rest_keywords = True
+else:
+    #
+    # Assume that all keywords are expanded properly everywhere:
+    # do not define special VCSxxx keyword below.
+    #
+    define_rest_keywords = False
 
 # -- General configuration ---------------------------------------------------
 
@@ -86,6 +122,17 @@
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'
 
+rst_prolog = """
+.. |release_date| replace:: %s
+.. |release_rev| replace:: %s
+""" % (release_date, release_rev)
+if define_rest_keywords:
+    rst_prolog += """\
+.. |VCSJustDate| replace:: %s
+.. |VCSRevision| replace:: %s
+.. |VCSHGRevision| replace:: %s
+""" % (release_date, release_rev, release_rev)
+
 
 # -- Options for HTML output -------------------------------------------------
 
@@ -96,7 +143,7 @@
 html_theme = 'haiku'
 # for the Haiku title
 html_short_title = u("%s %s") % (project, release)
-html_last_updated_fmt = "%s (rev %s)" % (current_date, configmix.__revision__)
+html_last_updated_fmt = "%s (rev %s)" % (current_date, release_rev)
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
@@ -146,7 +193,7 @@
     'babel': r'\usepackage{babel}',
     'preamble': r'\usepackage[stdtitle=false]{my-doc-style}',
     'maketitle': r'\builddate{%s}\vcsrevision{%s}\sphinxmaketitle' \
-      % (current_date, configmix.__revision__),
+      % (current_date, release_rev),
     'fontpkg': r'\usepackage[fonts=charter]{my-doc-fonts}',
 
     # Latex figure (float) alignment
@@ -159,7 +206,7 @@
 }
 latex_additional_files = [
     "_latex/my-doc-fonts.sty",
-    "_latex/my-doc-style.sty",    
+    "_latex/my-doc-style.sty",
 ]
 
 # Grouping the document tree into LaTeX files. List of tuples
@@ -219,8 +266,10 @@
 def setup(app):
     #
     # Custom release_date variable with a custom substitution |release_date|
+    # and |release_rev|'.
     #
     app.add_config_value('release_date', '', 'env')
+    app.add_config_value('release_rev', '', 'env')
 
     import sphinx.transforms
 
@@ -231,7 +280,7 @@
             from docutils import nodes
             for ref in self.document.traverse(nodes.substitution_reference):
                 refname = ref['refname']
-                if refname == 'release_date':
+                if refname in ('release_date' 'release_rev'):
                     stext = self.config[refname]
                     ref.replace_self(nodes.Text(stext, stext))