ls02 wrote:

What's the difference between RTD and CDX plywood for sheathing (walls
and roof) use? CDX appears to be twice as expensive as RTD. The walls
sheathing will be covered by house wrap.

RTD is short for "Rated." Rated for what? Well, it should be written
on the panel.

If it says "RTD SHTG", that means it's APA rated for use as sheathing,
and would thus be approptiate for your use on walls and roof.