On what and how are protocols written?

Question

Programming

Good evening, could you tell me what language the protocols are written in and what is this section called?

Answer 1

On the paper.

Answer 2

On paper, in English, and the section is called documentation.

Answer 3

The protocol is a description.
It can be written in simple human words, tables and pictures are additionally designed.
For specific implementations, special languages ​​are sometimes used - see protocol description language in protobuf.