How to define if brake pads suitble for carbon clinchers I have Carbon Tubeless wheels ZIPP 404 Weaponary 10 speed, which I have bought on my used Pinarello Ultegra rim brakes.
Now I hear that Carbon wheels should / must have special brakes.

Question is: How do I determine if I have right brake pads? and 

Is it MUST to be special pads for carbon, what if not?
Yes, you need special pads. Every manufacturer of carbon rims has their own recommendations for what pad to use, which you should follow. Zipp makes their own pads.

Normal brake pads are harder, and can wear away the carbon rim surface. This is very bad, of course. Brake pads for carbon rims are softer and wear down more quickly so that they preserve the rim.