A no-op; a CPU instruction that does nothing.
"The developer added a NOP instruction to align the code but noted that it could also be written in all lowercase as nop depending on the style guide."
Alternative letter-case form of nop
To replace machine code with nop instructions when modifying software.
"The developer noticed that the lowercase 'nop' in the assembly code was actually just an alternative letter-case form of the uppercase NOP instruction."
Alternative letter-case form of nop
Alternative form of nope
"After I asked if he wanted to join us for dinner, he just sent back a single nop."
A surname.
"The local history book highlighted that several prominent families in the town bore the surname Nop."