HEAD checks

[wilderness]

Absurd as this may sound!

If an IP and/or entity does a HEAD check, wouldn't it be a safe assumption that they have a cache file on hand for comparison?

205.188.116.79 - - [20/Apr/2012:01:06:43 +0100] "HEAD

I know it's long been a practice of AOL, however their membership taint what it used to be.

[MxAngel]

Not sure, I've seen many HEAD requests from the usual Twitter swarm. For example the twitter or bit.ly bot uses HEAD to check whether the URL is valid or not.

HEAD does return the full headers without the body / content so it could be used indeed to check if a ressource has been modified or not based upon LastModified/ContentLength.

[wilderness]

But, but. . .why on earth would they desire to check if the page changed unless they held a cache copy for comparison?