and the COIN module is..........?

Sorry, i thought this was widely known.

Its the "Construction Interface" shipped with Arma2 vanilla that allows mostly (but not limited to) building of fortifications, factorys etc (in fact you can configure it to build any available object in the class tree).

It provides an ingame GUI to do so that displays available money and a menu to select items.

so..... an RTS module for arma? i remember that, it DOES look interesting, but i think it should have more limits than it had in arma 2, you just dont make a barracks out of nowhere having money, you need to have basic walls materials, a building, sandbags, resources, vehicles to supply it, allies to defend it, etc.

I would say that that heavily depends on the actual mission concept.
For instance i made a mission ("Defend the base") that would heavily suffer from such restrictions.

While i agree with what you propose, i also want to point out that all that can be scripted.

What is needed is a stable core module for the basics that allow (like already it did in Arma2) such extensions. This way the mission maker has full control over the how and why of construction limits.

The COIN module in Arma 2 was my favourite feature. It gives a whole other dimention to warefare games and set Arma apart from the other shooters. Please implement and improve this BIS.

COIN module sounds more like an autogenerated counter insurgency campaign than Construction Interface, might wanna adjust what you call it accordingly.

If you have ever played the CTI warefare mode in Arma 2 or Warefare BE you will know what the COnstruction INterface is. Its not a mission, its a feature of the game that is currently missing from Arma 3.