[AnAmericanMother]

Roman coins of small denominations (and these look like quadrans (Roman) or obols (Greek) - very tiny copper coins) were minted in the provinces and used by the common people. They naturally had inscriptions in the local languages and pictures of the local gods. You'll find pictures of Serapis and Isis on Roman Egyptian coins, etc. In the entire east, the coinage was based on the Greek system of 1 drachma = 1 Roman denarius.

But a coin is not an "official record" - it's a medium of exchange.

[Destro]

But a coin is not an "official record" - it's a medium of exchange.

That is wrong. If you dared deface Roman money you would find yourself in the custody of the local cohort because you defaced an official symbol of the Emperor and the Empire. Remember the Jesus' remarks about who the money belonged to?

In any case, that was not the question. In the above you have physical proof that when Pilate himself designed the local coin of the realm the language he used for the legend was Greek. Thus indicating that historical writing does exist which can be shown to "prove" that Pilate spoke Greek in carrying out his administration, as per Hermann's question.