A little pet-peeve I have is when an obscure(ish) acronym is used and never defined. Is SERP a well-known acronym? Perhaps this is a niche blog and I'm not the intended audience.
(If I were writing something to be published, though, I would write "search-engine results page" instead of "SERP".)
SERP: Search Engine Results Page
That said, I do a lot of SEO work.
Still, it should be best practice to define any acronym or initialism the first time you use it