Hi
The following rule has led too some discussion in my club and in the end everybody has his own idea how it really has to be played:

"Models in this unit can be pipers. Once per turn, If an enemy unit ends its charge move within 3" of a unit that includes any Pipers, they can signal their unit to stand and shoot; each model can then shoot its Crossbow at the charging unit"

So the way I read this
Whenever an enemy unit ends its charge move within 3" of a piper , All units that include a piper get to shoot at the unit that ends its charge move within 3" of a unit with a piper.

The way some others read it:
Only units with a piper that have an enemy unit that ended its charge move within 3" can shoot at the charging unit.

The question really is about logic and the vague use of that they:
Does that "they" refer to "a unit that includes any pipers" => What I think
Or does it refer to the whole 3" ruling stuff to...

Which unit is this rule from?

sorry this is off course Free Guild Handgunners and Crossbowmen

Ok, the way I read it is that if a unit ends a charge move within 3" of a piper, only that piper's unit can fire crossbows at the enemy.

ok cheers
For me that they did not copy to the trigger mechanism of the ability ... and in that case it would have gone to all units with pipers if one of them got an enemy unit within 3" ... Well it would've been completely OP if it is like I said, and I would have had a pretty hard time defeating that army...

I mailed GW about it but I just got the standard mail that they might not reply to it and will take it with them making the game better in the future yadayadayada