Maʿrifat kunā al-musammayn
Identifying the kunyas of transmitters whose personal names are better known.
A transmitter may ordinarily appear under his given name yet be cited by a kunya in a different transmission. Confusing that kunya with another person's identity can distort the chain.
If a narrator is named explicitly in one route and referred to by a proven kunya in another, the change in wording does not create a new transmitter. Identity should nevertheless be established through a recognized kunya and compatible generation and teacher relationships, not through guesswork.