--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/docs/glossary.rst	Tue Mar 20 19:26:55 2012 +0100
@@ -0,0 +1,41 @@
+-----------------------------------------------------
+Vocabulary
+-----------------------------------------------------
+
+.. note:: all terminology is subject to change
+
+:obsolete marker:
+    express a relation from 0..n new changesets to 1 old changeset
+:obsolete changesets:
+    non public changeset target of a obsolete marker
+
+:unstable changeset:
+    changeset not obsolete but with obsolete ancestor
+
+:extinct changeset:
+    obsolete changeset without unstable descendant
+
+:suspended changeset:
+    obsolete changeset with unstable descendant
+
+:obsolete-parents:
+    previous versions of a changeset, through a direct obsolete marker.
+
+:obsolete-children:
+    new versions of a changeset, through a direct obsolete marker.
+
+:obsolete-ancestors:
+    previous versions of a changeset, through any number of obsolete marker
+
+:obsolete-descendant:
+    new versions of a changeset, through any number of obsolete marker
+
+:obsolete-diff:
+    diff between a changeset and it's obsolete parent
+
+:obsolete-tip:
+    obsolete-descendants not obsolete themself.
+
+:conflicting changeset:
+    multiple obsolete-tip for an obsolete changeset through diverging obsolete
+    marker (no changeset split marker)