In Asia this is especially significant, and errors can be insulting. Some automated sorting systems reject addresses containing full stops and commas. Others reject addresses without an area code. In international documents, specify the currency when you write sums of money. At least 24 different countries have their own dollar.
Many different countries have their own dinar, franc, peso, rial or pound.
Be consistent in the way you write numbers. There are no absolute international guidelines for the writing of numbers. Be aware of local conventions. Both these flaws bamboozle EFL readers. Long sentences are obviously confusing for people who are learning English as a foreign language.