IssueTargetOrder returns a boolean?

IssueTargetOrder returns a boolean?

I've seen this in a tutorial:

local boolean b = IssueTargetOrder(u, "attack",t)

I'm just interested, how does it return a boolean? What does this boolean show? I mean what do i get with it? Like is it attackable or what?
I saw that many native functions return a boolean (like this one). I don't understant.

Magic.

Well, I assume that it returns whether the process was successfully fired or not

Eg. return true for "stand", false for "arigablah"

But, thats just a guess. Theres not really much point using that anyways, as I cant see where that would ever come in handy... Who knows.

Interesting... I made an experiment around these functions and found things out. First of all, it's useless .
The commonly used UnitAddAbility also returns a boolean. I found that if you want to add an ability that the unit already has, it returns false. Else, it returns true, and adds the ability.
You were right about IssueTargetOrder: if the string field contains an unknown order, it returns false.
It seems, when these functions doesn't do the effect they are supposed to do, they return false.
Well that's it...

No, its not useless.

Its been used in some great custom functions out there, as also if there is an error in casting (not enough mana, untargetable unit/area, etc) it will return false and allows you to either do things like the IsLocPathable func by PitzerMike, or just an advanced way of debugging code

And course UnitAddAbility does . Around a year ago, I found out that about half the functions you expect to return nothing will instead return boolean