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
- Claude Sonnet 4.5 is probably the "best coding model in the world" (at least for now) - 29th September 2025
- I think "agent" may finally have a widely enough agreed upon definition to be useful jargon now - 18th September 2025
- My review of Claude's new Code Interpreter, released under a very confusing name - 9th September 2025