Cold pressure means before youve driven more than a few kms and the tires have not heated up.

The info RE Tire rating and PSI was derived from the website of a major European carmaker.

One of the first things I found on this forum was alot of complaints RE tires with "sidewall damage", cracking, blowing etc. Then getting replaced and doing it all over again.
Underinflated tires are more susceptible to damage (as are overinflated tires) but W and Y rated tires are supposed to be inflated to performance specs, not manufacturer specs. The sidewall pressure on Contis is 50 and 51 psi (front and rear are different), so they should be at 42.5psi. I keep mine at 40psi unless its a heat wave.