Having your Abap coding operate all over the world could mean some adaptions need to be done. There is a Unicode check setup available as transaction UCCHECK - Check a Program Set for Syntax Errors in Unicode Environment. The transaction operates as code inspector, checking the health of your ABAP developments. Unicode matters become important when talking to the outside world, so the interface side of developments is outlined here.
An ALV report will show the number of unicode errors found and details on each error can be listed from this report. There is also a unicode documentation button available on the selection screen, which describes quite nicely what this report can do for you and your system.