How do browser cookie domains work?

Question

Due to weird domain/subdomain cookie issues that I\'m getting, I\'d like to know how browsers handle cookies. If they do it in different ways, it would also be nice to know

Answer 1

There are rules that determine whether a browser will accept the Set-header response header (server-side cookie writing), a slightly different rules/interpretations for cookie set using Javascript (I haven't tested VBScript).

Then there are rules that determine whether the browser will send a cookie along with the page request.

There are differences between the major browser engines how domain matches are handled, and how parameters in path values are interpreted. You can find some empirical evidence in the article How Different Browsers Handle Cookies Differently