Sometimes your UI buddies just like the get in your way. It can be an overenthusiastic frigate captain who is blocking your fire path, or some high ranking schmuck on a cruiser who believes he has every right to not-so-gently nudge you out of his way. But the poor fellas can't really be blamed, AFAIK they don't even know in which of the allied ships their beloved admiral resides. And most of the time that's OK! You don't want them to start jumping to the side and saluting instead of shooting the enemy, every time you're around.
So, how can you teach your AI underlings the often fine difference between being obstructive and assertive? Just honk! Press a key, and every ally who's in the way of a) your current movement vector or b) the fire path of your currently selected weapon group immediately moves out of the way.