This has been requested many times, so i decided to consolidate all the request here:
Lazytt:
Most fields generate an error when I try to save them with hebrew text. (#1729)
andrew4455:
The display name doesn't allow the inputting of data in Lastname, Firstname format. It seems the , character is invalid. This would be useful so that you can get alphabetically sorted lists by last name for extensions, and other features, such as FOP. (#1880)
djelibeybi:
If you try entering a name like "Patrick O'Toole" in the Display Name field, FreePBX complains about not having an outbound CID configured. However, if you remove the apostrophe, it works fine. (#1532)
The reason for all the restriction is basically summed up by rob:
"...but allowing users to use ' in names won't be fixed for a while yet, possibly until 3.0, to avoid SQL injection errors."