OpenAI has released an addendum to the system card for its GPT-5.2 model, specifically for the Codex variant. The update provides more information on the training data and evaluation metrics used in the development of this model. --- Why it matters: This matters because it sheds light on the specifics of the Codex model's training data and evaluation methods, which can help researchers understand how to improve their own models. Source: https://openai.com/index/gpt-5-2-codex-system-card