we use "pak" when we meet someone that older than us or we call our bos. because " PAK" is more polite than we have to call their name

hello Pak White Tree,

It is you have been to my country very often. well to use Pak is when you meet someone older than you and also when you meet people somewhere on the street / cafe but you are not sure whether they are older/ ypunger than you , so just use PAK to be polite to others and also it represents your respect .

well it s not rude to call someone by their first name as long as you know that person very well or they ar eyour friends / anyone who are already close to you.

salam (cheers)

I missed something for your question: Well in a BUSINESS SETTING verbally and writting i suggest to say and write "PAK (refers to men and BU (for women). That's the proper one So for example in writing a business letter : To : Bapak Hasan ..... or To: Ibu Hasan

That;s also the same verbally if you are in business environment. Just use BAPAK (PAK) or IBU (BU)