The X-Robots-Tag HTTP header. News to me, but both Google and Yahoo! have supported it since last year. You can add per-page robots exclusion rules in HTTP headers instead of using meta tags, and Google’s version supports unavailable_after which is handy for content with a known limited shelf-life.
Recent articles
- The Summer of Johann: prompt injections as far as the eye can see - 15th August 2025
- Open weight LLMs exhibit inconsistent performance across providers - 15th August 2025
- LLM 0.27, the annotated release notes: GPT-5 and improved tool calling - 11th August 2025