No matter how hard you try, invalid data can creep into tables either by well intentioned users or by the odd programming error.

System delimiters stored in record ids can cause all sorts of odd behaviour, mainly centered around index retrieval.

the TABLE_DELETEINVALIDKEYS function will can a table for records that have a system delimeter or a null as a key and then remove them. Alternativly, the procedure will move the bad records to a backup table, changing any system delimiters into dots, so that you can scan through them to see if the data is worth keeping.