In my understanding, the net-id, subnet-id and host-id of a host IP address are portions of it, indicating which bits in its binary notation they corresponds to.
From them we can evaluate the network address and subnet address, which instead are IP addresses.
The converse is not true, unless you specify the subnet mask or CIDR.
In this way it does not make sense to specify the subnet-id with a single decimal number, f.i.
in 126.96.36.199/13 the subnet-id is the 5 most significant bits of the second byte, but if I specify the subnet address 188.8.131.52 without the CIDR or subnet mask I can't get the subnet-id. "176" does not specifies the subnet-id as 184.108.40.206/13 and 220.127.116.11/15 have the same "176" but different subnet-id's.
Is that correct? I see that in some textbooks the terms are used interchangeably.