What is "PE" paper? Polyethelene coated, aka RC?

I've been experimenting with Arista Private Reserve, aka Adox MCP 310 and 312, in both glossy and pearl respectively, myself. It is a very nice paper. I'm not sold yet on it versus Ilford MGIV RC. I need to work on these some more. I dislike RC glossy except for contacts where the smoothness helps with showing all detail possible under a loupe, but the Ilford Pearl and Adox/Arista 312 are very nice surfaces, not too much hit to d-max relative to the glossy and they look quite a bit like FB glossy-dried-matte.