Maybe we need to update #RTFM. Actual manuals are rare beasts these days. You’re more likely to find the information you need online, whether it’s in the form of PDF datasheets, forum posts or Git gists.
It should really be RTFAI, in which the AI isn’t what you think but stands for ‘Available Information’. But that’s a bit of a mouthful, so perhaps just RTFI. Or we could just say ‘Read’, followed (if you feel strongly about it) by FFS. RFFS?