True Sight, how far does it go?

okay, we need to get this all out on the table for RP reason, what can true sight see or not see though, i know some standard illusions, some say all magical illusions, most stealth *except very, very good stealthers* but can it see through a polymorph, i know it can;t see through a shift from a druid since they actually change into the creature, but does a poly potion or polymorph spell work in the same way? could a DM please clarify this.

polymorph is not an illusion to be seen through was my understanding. The difference between polymorph (assuming a shape) and shapechange (becoming the creature) is more about what abilities you get in the new form.

I'll try to find some links on this later.

Be well. Game on.
GM_ODA