Sifra on melikah of the bird chatas.
English: “Opposite its nape” — from the back of the neck; “he shall not sever” — he does not separate the head from the body, distinguishing the chatas bird from the olah bird.
Custom (procedural contrast chatas vs olah bird).
Bird chatas is killed by nape melikah without full detachment of the head; this marks it off from the bird olah.