PT is platinum and PD is palladium. According to the relevant national standards of precious metals, platinum jewelry will not be marked with PD if it is marked with PT plus purity. In addition, if PD palladium jewelry is marked with PT, it does not meet the national standard. If you ask whether it is true or not, then look at the letter sign, which can only be called as conforming to the national standard, but not the standard. If you want to know the truth, you must send it to an authoritative jewelry testing institution or technical supervision bureau for testing.