diff --git a/cli/doc.py b/cli/doc.py
new file mode 100755
index 0000000..3ae37b3
--- /dev/null
+++ b/cli/doc.py
@@ -0,0 +1,66 @@
+#
+# Copyright (c) 2012,2013 Big Switch Networks, Inc.
+#
+# Licensed under the Eclipse Public License, Version 1.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+#      http://www.eclipse.org/legal/epl-v10.html
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# permissions and limitations under the License.
+#
+
+import os
+
+#
+# doc, interface to manage 'markdown' text segments based on 
+# documentation tag's.
+#
+
+doc = {}
+
+def register_doc(tag, path):
+    """
+    Its not clear whether the registratio api ought to only name
+    the available tags, or whether the api ought to also associate
+    text, but it seems that it would be wiser to not keep all the
+    documentation in memory
+    """
+
+    doc[tag] = path
+
+def add_doc_tags(base, tag_prefix = None):
+    path = base
+    if tag_prefix == None:
+        tag_prefix = []
+    elif type(tag_prefix) == str:
+        tag_prefix = [tag_prefix]
+
+    if os.path.exists(path):
+        for elem in os.listdir(path):
+            this_tag_prefix = list(tag_prefix)
+            this_tag_prefix.append(elem)
+            full_path = os.path.join(path, elem)
+            if os.path.isdir(full_path):
+                add_doc_tags(full_path, this_tag_prefix)
+            elif os.path.isfile(full_path):
+                register_doc('|'.join(this_tag_prefix), full_path)
+            else:
+                print 'add_doc_tags: unknown file type for ', full_path
+
+
+def get_text(context, tag):
+    path = doc.get(tag)
+    if path:
+        if os.path.exists(path):
+            with open(path, 'r') as f:
+                return f.read()
+        else:
+            if context.sdnsh.description:
+                print 'doc: tag %s: missing ' % tag
+            
+    return ''