Tracy will have the final say, as he wrote the code, but most likely:

 

NOP = No Operation.  or Non Operational.   Uh for the life of me I can not recall when I started using that notation, but if you flag part of a  schematic, or assembly code, with NOP it is pretty universal comment among geeks (EE's).

 

At least it isn't flashing "Fubar". :)   Once I "inherited" some assembly code on a project which had never been commented (debug/maintenance nightmare). Thankfully the previous engineer had a hard copy with his hand written Chinese notation along side the code. Excited as I started to recognize a pattern of hand written characters by the sections of code I couldn't figure out. Thankfully another engineer  explained what "fubar" looked like in Chinese.

 

Tom