What does Priority=High mean in the Set-Cookie header?

Question

I've been looking at Chrome's traffic in Fiddler, and I found something that I feel I don't understand:

Set-Cookie: GAPS=1:ZYBtVMzURzU2umKMxZThJ2lVPxy3Hg:SvHhlG2k1Vy5pnA0;Path=/;Expires=Wed, 04-Nov-2015 20:44:37 GMT;Secure;HttpOnly;Priority=High

I can't find any documentation on what Priority=High is for. What does it mean?

Answer 1

Basically this is a spec by at least chrome (I didn't see it for other browsers) that allows cookies to be prioritized for when they are re-authenticated. Cookies get deleted when they exceed per-domain cookie capacity. The cookie-priority allows servers to remove old cookies at lower priorities, and hang onto higher priority cookies longer, despite being older.

More information can be found here