@@ -621,7 +621,11 @@ There are four kinds of changes that may be made to a node in a `desk`.
621621
622622`%ins` inserts a file given by `p`.
623623
624−`%dif` is currently unimplemented.
624+`%dif` is currently unimplemented. This may seem strange, so we remark that
625+diffs for individual files are implemented using `+diff` and `+pact` in `mark`s.
626+So for an `ankh`, which may include both files and directories, `%dif` being
627+unimplemented really just means that we do not yet have a formal concept of
628+changes in directory structure.
625629
626630`%mut` mutates the file using raw data given by `p`.
627631