>Concatenated keys are used in almost databases. I just want to know if it will be managed without problemns by VFP database engine.

You're going to run into the same problems that you would in any other database...cascading changes to the fields that make up the PK. You'll also have to check for duplicates everytime. Again, this is not a good choice for a PK. You can use it for a regular key, but PKs should not be based on data entered by the user.