+However, use of git-debrebase in Debian does not make anything harder for
+derivatives, and it can make some things easier.
+
+=head1 TERMINOLOGY
+
+=over
+
+=item Pseudomerge
+
+A merge which does not actually merge the trees;
+instead, it is constructed by taking the tree
+from one of the parents
+(ignoring the contents of the other parents).
+These are used to make a rewritten history fast forward
+from a previous tip,
+so that it can be pushed and pulled normally.
+Manual construction of pseudomerges can be done with
+C<git merge -s ours>
+but is not normally needed when using git-debrebase.
+
+=item Packaging files
+
+Files in the source tree within B<debian/>,
+excluding anything in B<debian/patches/>.
+
+=item Upstream
+
+The version of the package without Debian's packaging.
+Typically provided by the actual upstream project,
+and sometimes tracked by Debian contributors in a branch C<upstream>.
+
+Upstream contains upstream files,
+but some upstreams also contain packaging files in B<debian/>.
+Any such non-upstream files found in upstream
+are thrown away by git-debrebase
+each time a new upstream version is incorporated.
+
+=item Upstream files
+
+Files in the source tree outside B<debian/>.
+These may include unmodified source from upstream,
+but also files which have been modified or created for Debian.
+
+=item Delta queue
+
+Debian's changes to upstream files:
+a series of git commits.
+
+=item Quilt patches
+
+Files in B<debian/patches/> generated for the benefit of
+dpkg-source's 3.0 (quilt) .dsc source package format.
+Not used, often deleted, and regenerated when needed
+(such as when uploading to Debian),
+by git-debrebase.
+
+=item Interchange branch; breakwater; stitched; laundered
+
+See L</BRANCHES AND BRANCH STATES - OVERVIEW>.
+
+=item Anchor; Packaging
+
+See L</BRANCH CONTENTS - DETAILED SPECIFICATION>.
+
+=item ffq-prev; debrebase-last
+
+See L</STITCHING, PSEUDO-MERGES, FFQ RECORD>.
+
+=back