Re: [PATCH v2 12/15] Documentation/technical: describe multi-pack reverse indexes

+== multi-pack-index reverse indexes
+
+Similar to the pack-based reverse index, the multi-pack index can also
+be used to generate a reverse index.
+
+Instead of mapping between offset, pack-, and index position, this
+reverse index maps between an object's position within the MIDX, and
+that object's position within a pseudo-pack that the MIDX describes.
+
+To clarify these three orderings

The paragraph seems to only describe 2 orderings - object's position
within the MIDX and object's position within the pseudo-pack. (Is the
third one the offset within the MIDX - which is, I believe, trivially
computable from the position within the MIDX?)

Also, which are stored in the .rev file?

The previous patches look good to me, and I'll review the remaining
patches hopefully tomorrow.