Having caught Dan Crow’s initial mention last week of the unavailable_after META tag, I was pleased to see Barry do some due diligence and hook us up with some more quality information.
As is often the case, you’ll never get a copy of a Google engineers presentation… Barry managed to get some examples of how to put this tag to use in his post over on SearchEngineLand called More Info On Google’s Unavailable After Meta Tag & New X-Robots-Tag In Header Support.
While the unavailable_after examples are pretty standard stuff, it was also good to see some X-Robots-Tag usage. Quoted from above referenced post on SEL…
Here are examples of how to use the X-Robots-Tag:
Don’t index this document:
Don’t show cache or snippet in search results for this file:
X-Robots-Tag: noarchive, nosnippet
Don’t index after a specific date (i.e. the “unavailable_after” tag):
X-Robots-Tag: unavailable_after: 7 Jul 2007 16:30:00 GMT
You can also combine these tags as well.
Danny has more on Meta tags at Meta Robots Tag 101: Blocking Spiders, Cached Pages & More.