You need to provide more detail. Valid for what purpose? It can be valid proof the letter was sent to you but it cannot be valid proof of a contract. Details are important.
Foreign drivers licenses are generally valid in the US as long as they are accompanied by an International Driving Permit (IDP) and are in English or have a certified English translation.
depends on country & regions
Yes it is valid proof of marriage. The joint agreement is signed by both in the presence of winesses.
Dog licenses are issued locally, so the length of time they're valid varies from place to place.
They are usually not valid.
Yes, US marriage licenses are generally not valid internationally. Couples who wish to marry abroad may need to follow the specific marriage laws and requirements of the country in which they plan to wed.
It is ALWAYS valid. If you purchased something, the bill of sale is proof of that.
There are an infinite number of twin primes. This is true, but as yet there has not been published a valid proof of it. Perhaps soon someone will publish a valid proof.
All state driver licenses are valid in every other American state.
It would be a violation of the licensing law in Floridas. You are not allowed to have more than one valid license and a suspended license counts.
Well there are a couple of pics but mostly not entirely valid.