Because this suggestion was so unpopular, I have proposed a new synonym request here: Request GCD synonym to Greatest Common Divisor
GCD generally refers to problems regarding greatest common divisors. This should not be used for Apple's Grand Central Dispatch (use grand-central-dispatch for that).
The thing is, "GCD" is, with no offense to the 8th grade math students out there, is definitely best known in this forum as the abbreviation for Grand Central Dispatch. In fact if you look at the GCD tagged questions, most of them are Grand Central Dispatch related, despite the current admonishment of the gcd tag excerpt.
I would like to propose changing the gcd tag be redefined to be a synonym for Grand Central Dispatch. But I hesitate to just blithely edit the definition to be the precise opposite of the existing definition. Clearly I could just make the edit and see if it's approved, but that doesn't feel quite right.
What the correct protocol is here?