The rule is Human = All species in Homo unless otherwise stated. You’ll see some papers say things like, " In this review when I speak of humans, i am referring to H. sapiens." Atleast that’s how I’ve been taught and what I’ve experienced.
If that is a rule, it is very recent. In the literature the meaning of “human” is very unstable, sometimes appearing to take on more than one meaning in a single paper.
Oh I know it can get confusing. Just saw the the term “Early Modern Human” in a paper. Which is just confusing
In my view, it’s fine to use the word human in scientific work as a gloss, but nothing more. All scientific claims need to be stated in neutral terms that stand independent of the wide range of meanings of “human”. When this rule is violated, we are forced to back out the real meaning of the data. Otherwise we just encounter an incoherent mess of confusing dialogue. “Human”, we should expect, is not going to correspond neatly, without debate, to any taxonomic category. Taxonomy should continue, and they were wise not to make any of our scientific names literally be “human”.