I am trying to analyze the code contributed by David Abrahams back in 2004 to see if I can clean it up, bring it up to date, streamline it and thus resubmit it for inclusion in the next update. I tried svn merge 2755:HEAD of the main line into the branch (2755 is the last time Mr. Abrahams merged the mainline in with his branch) with below average results; I tried merging his branch 1813:HEAD (1813 is the re-factored cvs2svn version number of when his branch was spawned) with mixed results. There're been a number of changes the main line since he wrote this in 2004 to even the the main file he changed: docutils/parser/rst/states.py and they are complex so I'm trying to have a go at it but have only just started. I spent most of yesterday struggling with merge so I've only just started looking at the code now; I will update this artifact as I make significant progress and will post my request for help, if needed, here. Of course, help is always welcome. Thanks.
FYI, the nesting branch is a solution which would allow authors to nest inline markup, i.e. *emphasize |H2O| in a **proper** :custom:`diet`*.