A System Card in the context of AI, particularly regarding OpenAI's GPT-4o, is a detailed document that outlines the capabilities, limitations, safety measures, and ethical considerations associated with the AI model. This card is designed to inform users and developers about the model's performance, including potential risks and how they are mitigated. It also addresses the model's training data, biases, and the steps taken to ensure responsible usage. System Cards aim to enhance transparency and accountability in AI deployment, offering insights into how the model functions and its potential impacts.

For the GPT-4o System Card, you can find more details here.