OpenAI Codex system prompt includes explicit directive to "never talk about goblins"

OpenAI's Codex system prompt for the latest GPT-5.5 model explicitly prohibits mentioning goblins, gremlins, and other creatures unless directly relevant to user queries. The directive, absent in earlier models, emerged in a 3,500-word base instruction set and follows user complaints about the model's recent focus on unrelated goblin references.