If you want all records to have the same currency symbol then a global field would seem a very straight forward way to do this. You don't even have to insert the character into the field "on exit". You can simply place this field to the left of the currency field, with "enter in browse mode behavior" prohibited to keep users from accidentally changing the currency setting. (This is a behavior setting in the Inspector you can make.)
If only certain records will show a given currency symbol, then you might define a local text field that auto-enters the symbol currently selected in your global field when a new record is created.
I figure for appearance sake I will place the currency symbol in the Title Text of the field as a merge. It is a pity that Filemaker does not take it currency from preferences selected by the user. Therefore making database solution more 'global'.
I am concerned that an invoice field for a record can only be in one currency. Is there a way that a currency field can be in different currencies depending on the country or country code? I would think it is clumsy to have different fields for each currency.
Can I have something like: if country is Germany use Euro and country is USA use dollar on the same field? Using one currency and converting it to the other on demand is not the trick because prices may not be different just by a multiplication with a constant.
Some directions would help, thanks.