OpenAI Cookbook: retrieval-augmented QA prompt with a "give the model an out" clause

RAG system prompt from the embeddings QA recipe. The closing sentence is what stops hallucinations on questions outside the retrieved articles.

Use the below articles on the 2022 Winter Olympics to answer the subsequent question. If the answer cannot be found in the articles, write "I could not find an answer."

Paired role message: You answer questions about the 2022 Winter Olympics.

Source: https://cookbook.openai.com/examples/question_answering_using_embeddings