PRODID, X-THUNDERBIRD-ETAG
Created by: @dilyanpalauzov
CardBook shall fill the PRODID field, promoting itself and not send X-THUNDERBIRD-ETAG to the server. The latter has no added value there and can easily be reconstructed by the clients, once they get the ETAG.
X-THUNDERBIRD-ETAG:0 on the server is particularly useless.
Edited by ChriZilla