let me just state the order of names is not standardized in Europe either, darn Hungarians.
(Nobody actually cares, but I do get constant confusion as a foreigner in Budapest because people sometime expect surname-first and sometimes given-first, trying to accomodate for me)
Something I've seen genealogists do, as well as some French-speaking Lebanese, and maybe others that I haven't noticed or encountered, is to put the surname in all caps to disambiguate e.g. 'Harrison Paul JEFFERSON'
Same situation in Greece. Formal documents like identity cards, university diplomas, and even mailboxes, generally put the surname first, while in running text, like a news article, the given name is first. Some formal documents also list the patronymic, in the order: Surname Given Patronymic.
In some situations it is less clear which convention applies. For example most of my older relatives use surname-first for their Facebook account name, which is less common with younger people. I have also seen both orders on business cards. I think most Greeks would not expect foreigners to be familiar with or follow these conventions though.
"Hungarian is one of the few national languages in Europe to use the Eastern name order, like Chinese, Japanese, Korean, Vietnamese and some Basque nationalists."
It's not unheard of in the UK either on official documents to put last name first, for example a lot of correspondance from banks etc would be "to mr lastname firstname"
(Nobody actually cares, but I do get constant confusion as a foreigner in Budapest because people sometime expect surname-first and sometimes given-first, trying to accomodate for me)