[Original] cookie domain naming rules

A Set-Cookie2 from request-host y.x.foo.com for domain = .foo.com wocould be rejected, because h is Y. X and contains a dot ....

A Set-Cookie2 from request-host x.foo.com for domain = .foo.com wocould be accepted ....

A Set-Cookie2 with domain =. com or domain =. com., will always be rejected, because there is no embedded dot ....

A Set-Cookie2 with domain =. com or domain =. com., will always be rejected, because there is no embedded dot ....

A Set-Cookie2 with domain = ajax.com will be accepted, and the value for domain will be taken to be .ajax.com, because a dot Set-Cookie2 with domain = ajax.com will be accepted, and the value for domain will be taken to be .ajax.com, because a dot gets prepended to the value ....

 

Http://www.rfc-ref.org/RFC-TEXTS/2965/kw-domain.html