How to get a Document Number in a response from BAPI?

Hi All,

We are calling BAPIs from MII, and we would like to know if there's a way of figuring out the document number returned from the BAPI. Do we have a unique identifier like a key, that we get back from the BAPI? If not, then how do we go about fetching the document number?

PS- I'm referring to BAPIs in general and not any specific BAPI.

Please advise or share any links/posts.

Thanks,

Rajeev