I agree, but it's a hard balance to strike and depends on the writer's target audience. RACI is a pretty common acronym for anyone doing project management professionally. I'd not define REST, HTTP, etc; in an engineering doc.
Details can be hard, even if small. Don't get me wrong, I try to do it myself every time I write, but I often find myself wondering if it's worth to link to a definition or will it be too obvious and come across as condescending. Maybe is just me.