Sources about the praefectus castrorum

[Principe Alessandro]

Greetings, I'm a new Roman Army Talk member, I followed this forum for some time and I see that there are a lot of people with good knowledge about the Roman Army so I registered to ask some help for my final thesis at my University.
I mostly need sources about a key officer of the imperial army (the praefectus castrorum).

I have already found a list of sources about different camp prefects but I cannot understand what is the meaning of the abbreviations aside the ones pointing to ancient authors.

Here are the lists:
http://prntscr.com/1s83vn
http://prntscr.com/1s841h
http://prntscr.com/1s845z
http://prntscr.com/1s84ci
http://prntscr.com/1s84jd
http://prntscr.com/1s84p0

Also if somebody has more sources I'll gladly look on them.

Regards