What makes laserply a laserply?

Technically speaking, what makes laserply a laserply which is so easy to cut ?
Could someone in the know educate me on glues/formaldehyde technical aspects, terminology, etc ?

Been buying plywood from local suppliers, some of the ply cuts beautifully, some absolutely unworkable. Just recently bought a load of 6mm birch interior ply which is absolutely unusable for laser cutting application, looks nice, wont cut. On the other hand i bought some construction ply which looks nasty unfinished, but cuts like a dream.
And i have no idea what questions to ask of the supplier when it comes to construction of the ply in regards to laser cutting. They usually deal with spindle CNC people, not laser people, so they have no clue about that unless asked about ply tech specs directly.

2 things, I think: 1. all the plys should not have knots and be fairly regular grain. 2. Glue layers that are fairly thin and do not contain chemicals that create unhealthy fumes when burnt. That said, I have received plywood from a laser supplier company that purports to sell laserable plywood, and some of the pieces did have knots inside and such hard glue spots the laser did not cut through. Even they do not x-ray sheets to see what’s hidden inside!

I have no chemical expertise but believe that formaldehyde in adhesives has been very limited for indoor wood panels (in the EU) for some years.
Plywood is available in an awful lot of variations and is primarily subdivided into indoor and outdoor (interior / exterior) plywood. My experience is that the dark glue from exterior plywood is harder to cut, it’s just like the glue melts and can not really evaporate. Imagine a sandwish of birch veneer, acrylic, filler, acrylic and birch wood veneer again and that in 3-6 layers. Of course it is not acrylic but it reacts a bit as if it is a plastic product and also has completely different cutting properties such as wood. The filling layers also have a great influence, they can be anything from waste shavings to normal wood veneer, plywood with white glue and poplar filling layer is relatively light and very easy to cut. For the products I make, I buy “laser suitable airplane BB plywood”, the interior type. It is expensive but can be processed well and is without too many inclusions and glue pockets.
Asian plywood is very rare here in Denmark and I have no experience with it at all.