Why does the default ASP.NET Forms Authentication Cookie have a leading period in it's default name => ".ASPXAUTH"

Question

the default ASP.NET Forms Authentication cookie sets it's name as ".ASPXAUTH". Notice the first character is a period? Is there a particular reason for this? Like, does this have an impact on domain names or subdomains for the target domain.

Or is it purely some random thing an MS dev person came up with (maybe to help out the ordering of the cookies, when they were debugging or something .. as text with periods prolly get listed before other strings)?

Answer 1

The cookie in the same is completely optional and simply reduces the likelihood that you'll overwrite a different cookie that might be set by your code. The two-dot requirement is related exclusively to the domain name.