In RFC7616 for Digest Authentication, the nonce count (nc) is described as
The nc value is the hexadecimal count of the number of requests (including the current request) that the client has sent with the nonce value in this request.
and in the same RFC, the explanation for nonce states that:
A server-specified string which should be uniquely generated each time a 401 response is made.
What I don't understand from the RFC is under which circumstances the same nonce is ever used again in a response that required the nonce count to ever be incremented.
Any explanation?