SAP Message 3L222 - First 4 CURP positions must be alphabetical "&"

Diagnosis
You have entered numbers or blanks in the Population Register SingleCode instead of the required alphabetical characters .
The first four CURP characters must be letters and must not have anyblanks in between.

System Response
The system interrupts the program run.

Procedure
Make the corresponding changes in order to correct the CURP.