People often cite earlier work - a paper, an email, etc. instead of explaining something. If you actually want to communicate, you swallow your pride and unpack the thing. It is a form of compression similar to Jargon. Jargon is mystifying to people without the relevant context. It’s worse than Jargon because if you need to mention the paper, you know for sure that the person hasn’t heard of it so it never helps communication. It has the benefit of at least telling someone where to get the context.
People do this for two reasons:
It’s isomorphic to ‘I put it in the email’ and ‘read the docs’