I was reading the answer of this questions here: Share cookie between subdomain and domain
It does not answer one of my question what if we want to push it one level further by having a sub2.sub1.domain.com
Can an application hosted on sub2.sub1.domain.com set a cookie on .sub1.domain.com ?
and then would this cooke be available for an application on sub1.domain.com and not available on an application on sub3.domain.com?
If so is that supported by all the browsers? I am trying to find the RFC specification that would either show that this is possible or impossible.