[frognumber]

False.

There is a 3-level hierarchy:

System prompt > Developer prompt > User chat

You provide that middle level.

[ta988]

Source

[th0ma5]

Ther may be actually no way to ever know. A baked in bias could be well hidden at many levels. There is no auditing of any statements or products from any vendor. It may not be possible.

[frognumber]

It's common knowledge. See, e.g.:

https://lunary.ai/blog/openai-developer-role