Computer Protocol

All communication protocols start with declaring you are open to communicate and hint at what language we are open to communicate in.

Is the other person/computer safe to talk to? What is their status? What information can be shared with them?

Just like in human Conversation

If a computer isn’t running software which is compatible then the conversation doesn’t work.

Likewise two humans that don’t have compatible language, ideas and beliefs about the subject matter in kind have a hard job communicating with each other.

This is also a Systems Exchange for the presumed benefit of both systems.