The 'Cookie support' dimension reports if the browser supports cookies for a hit. It is useful to determine the ratio of visitors who use browsers that support cookies, and those who have disabled the cookies.
This dimension collects data from the 'k' parameter in image requests. AppMeasurement tries to set a cookie named s_cc , then detects if the cookie exists.
So, if your browser is configured to accept the cookies then this parameter will set to 'Y' as shown below.
However, if you configure your browser not to accept the cookies then the 'k' parameter will set to N.
But, if the s_cc cookie is not set in your browser or 'k' parameter is not set in the server call then this dimension will be set to 'Unknown' line item.