Another possible reason not outlined the other replies you received to this comment - If I were to say "copy the raw file" someone less experienced may think "o

Another possible reason not outlined the other replies you received to this comment - If I were to say "copy the raw file" someone less experienced may think "okay, take the fresh jpeg file and copy it", interpreting "raw" in a more conventional, non-technical sense. Capitalizing it emphasizes that it refers to the file format, even if not the actual file extension. Sure, I could say "copy the NEF file" or "copy the CRW/CR2 file", but that means I'd have to know whether the user was using Nikon or Canon. "RAW" lets the speaker eliminate ambiguity in non-technical contexts without needing to be so specific as naming the actual extension.