What kind of question is it?
If nothing is specified, it is obvious that it is still a value between 1 and 255, and the default is 1.
No matter, the default permit “ping”.
Using search function give results…
http://forum.mikrotik.com/t/buying-rb1100ahx4-dude-edition-questions-about-firewall/148996/4
“hide-sensitive” do not hide anything sensitive on IPv6, and on some version of v7 is not present at all…