>One comes across various abbreviations e.g. M or MN for majjhimanikaya. Is
>there such a thing as an official list of standard abbreviations?

I think the reason for M, instead of MN is by analogy with S for
Samyuttanikaya. If you use SN for the latter, it gets confused with
the Sutta Nipata. So for consistency's sake it makes sense to use a
single capital letter for all the Nikayas, especially considering
their central importance.

>I don't have a PTS dictionary or other PTS books with them in, only the
>Visuddhimagga or Bhikkhu Bodhi's Majjhimanikaaya. Does anyone have a text
>file handy they could post?

The abbreviations in Cone's DoP might be a good choice for such a
list. If noone shows up who has it (or something similar) already in
a text file, I could type it in.

best regards,

/Rett