<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>We are about to change the format of the mwLastWriteTime cookie.<br></div><div><br></div><div>For reference, this cookie is used as a cache control mechanism, as described here:<br><a href="http://blog.freebase.com/2008/01/22/caching-dynamic-content/">http://blog.freebase.com/2008/01/22/caching-dynamic-content/</a><br></div><div><br></div>You should never be parsing the value of the mwLastWriteTime cookie. It's intended to be an opaque token. Unfortunately, there are a few systems that have to inspect these. If you're one of those, please pay attention to the following.<div><br></div><div><br></div><div>The current cookie format contains a time value and a guid, separated by a pipe character:<br><br>mwLastWriteTime=1225749629|9202a8c04000641f8000000009b1d1b0<br><br>We are adding the database instance that generated that guid at the end as an additional value, so the new cookie will look like this:<br><br>mwLastWriteTime=1225749629|9202a8c04000641f8000000009b1d1b0|sandbox<br><br>If your application always talks to the same freebase service (e.g. <a href="http://www.freebase.com/api/mqlwrite)">www.freebase.com/api/mqlwrite)</a>, you can ignore the value of this last parameter and continue using the other two values as before.<br><br>The intent is to allow us to issue this cookie at a lower level domain (such as .freebase.com) but still be able to correctly identify which cookie value is meant for which graph instance in the case where multiple mwLastWriteTime cookies exist.<br><br>These changes are coming in the following days, so please let us know if you will need more time to accommodate them.<br><br>Thanks,<br>Michael Masouras</div><div><br></div></body></html>