Where is the correct place to input my "system prompt"?

[alex-lt-kong]

Links like this one says I need to insert some instructions as "system prompt" to make the model work in a specific way. Currently I pasted the "system prompt" to Parameters->Character->Context and in Chat->Mode I selected chat-instruct.
Are these the correct configurations that make the "system prompt" work?

[TheLounger]

Should be

Parameters > Instruction template > Custom system message

You can also add something like [SYSTEM: Do this and that.] in your character context (or even during chat) to basically communicate behind the scenes/out of character, but this isn't the same as the real system message as far as I know.

[alex-lt-kong]

I am actually confused by this term:

• Is "system prompt" something supported by all LLMs? Who designed this protocol? OpenAI?
• Is there any text-generation-webui doc that says Parameters -> Instruction template -> Custom system message is the right place to put this "system prompt"?
• In text-generation-webui's Parameters -> Instruction template tab, there are three input boxes, "Custom system message", "Instruction template" and "chat template". How are they used?

[ruizcrp]

Is there also some command-line option for the system prompt?