What does "who gaf" mean?

The phrase who gaf is informal internet slang and texting shorthand that means who gives a fuck, which is a vulgar way of saying who cares or nobody cares. Gaf in this context is short for give a fuck, which itself is short for give a fuck or give a f***, an intensified version of give a damn. So who gaf is asking dismissively who cares about something, implying that nobody cares or that the speaker does not care. For example, someone might say who gaf about that celebrity drama meaning who cares about that celebrity drama, or if a friend says did you hear about the new rule, someone might reply who gaf meaning I don't care. The phrase is considered vulgar and informal due to the profanity implied by fuck, so it is used mainly among friends, in online gaming, social media, and texting, not in formal or professional contexts. It is often written in lowercase as who gaf, who gaf, or as part of the larger acronym IDGAF meaning I don't give a fuck. The spelling gaf for give a fuck is common in UK, Irish, and Australian youth slang where gaf is used as shorthand to avoid typing the full profanity while retaining the same meaning. It is similar to saying who cares but with much stronger, dismissive attitude.