CCL FR-4 1.5MM copper containing no watermark, with copper containing watermark what is the difference?

CCL FR-4 1.5MM copper containing no watermark, with copper containing watermark what is the difference?

There are many manufacturers of CCL, and each manufacturer has its own unique watermark character, similar to the anti-counterfeit trademark.

Hello! Whether or not there is watermark copper clad laminate, except for the watermark character on the surface of the base material, the properties of other boards are the same;