How To Fix GB123 - Rule must begin with a letter

GB123 - Overview

• Message type: E = Error

• Message class: GB - Messages used by the Boolean code generator

• Message number: 123

• Message text: Rule must begin with a letter

What causes this issue?

You have attempted to create a subrule with a name that does not begin
with a standard alphabetic character. The first digit may not be
numeric. Only characters belonging to the international character set
are supported.
'ABCDEFGHIJKLMNOPQRSTUVWYXYZ'

System Response

None

How to fix this error?

Choose a different name.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.

GB123 - Details

• The SAP error message "GB123 Rule must begin with a letter" typically occurs in the context of defining or configuring rules in SAP, particularly in areas like validation, substitution, or other custom rules where a naming convention is enforced.
  
  Cause:
  The error indicates that the rule name you are trying to create or modify does not start with an alphabetic character (A-Z, a-z). This is a requirement in SAP to ensure that rule names are valid and follow the naming conventions set by the system.
  
  Solution:
  To resolve this error, you should:
  
  
  Check the Rule Name: Ensure that the rule name you are entering starts with a letter. For example, instead of using a name like "123Rule" or "_Rule", you should use "Rule123" or "A_Rule".
  
  
  Modify Existing Rules: If you are trying to modify an existing rule that has an invalid name, you will need to rename it to comply with the naming convention.
  
  
  Follow Naming Conventions: