Like the one that looks like a target with three glowing arrows over it. And all the others that aren't described in the map itself. And what does it mean when you can see the squad beacon on the map but it's not green and you can't spawn at it? Somebody needs to put this stuff on the wiki damnit!
The target is a squad leader requesting help attacking. Often good squad leaders will mark enemy sunderers with them; other times it's just a request for more players to join the fight. The shield icon is the same deal, but for requesting defenders. The beacon is a friendly or enemy spawn beacon that's not part of your squad.
You can see everyone's spawn beacon even if you're not in a squad with them, if they're not green then they're from someone outside of your squad. I think that you mean the squad objective marker when you say a target with three glowing arrows over it. The Squad Leader can select an capture point on the map as the objective in order to show the squad which cap point has priority over the others e.g squad marker on B means that A and C are somewhat secure or that there's little threat there and that they need you to come help at B rather then staying at C or A =)
while they should probably add say a manual on the site or a legend in game it wouldn't matter... not only do most never even read them and complain anyway but common sense and a few minutes of experience should answer these questions before the need
