How To Fix NP231 - Field name & is reserved (Structure cannot be used as append in DB table)

SAP Error Message - Details

• Message type: E = Error

• Message class: NP - New checks in the activating program

• Message number: 231

• Message text: Field name & is reserved (Structure cannot be used as append in DB table)

What causes this issue?

In an append structure, you are using a field name which is reserved
for the database.

System Response

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

How to fix this error?

This will not result in an error as long as you do not use the
structure as an append structure in a database table.
You may not use the table as an append structure in a new database
table and may not use it as a new append structure for a database table
which is already active.
The table activation program rejects it because use of this database
table can cause errors, depending on the database system.
A warning is given for tables which are already active having such an
append structure.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message NP231 - Field name & is reserved (Structure cannot be used as append in DB table) ?

  The SAP error message NP231 indicates that a field name you are trying to use in a structure is reserved and cannot be used as an append in a database table. This typically occurs when you are trying to append a structure to a database table, and one of the fields in that structure has a name that is reserved by the SAP system.
  Cause:
  
  Reserved Field Names: SAP has a set of reserved field names that cannot be used in custom developments. These names are often used by the system for internal purposes.
  Field Naming Conventions: The field names in your structure may not comply with SAP's naming conventions, which can lead to conflicts.
  Existing Fields: If the field name you are trying to use already exists in the database table or is part of the standard SAP structure, it will cause this error.
  
  Solution:
  
  Rename the Field: The most straightforward solution is to rename the field in your structure to something that is not reserved. Ensure that the new name follows SAP's naming conventions (e.g., starting with 'Z' or 'Y' for custom fields).
  Check Reserved Names: Refer to SAP documentation or the ABAP Dictionary to check for reserved field names. You can also use transaction SE11 to look up existing fields in the database table.
  Use a Different Structure: If renaming is not feasible, consider using a different structure that does not contain reserved field names.
  Review Append Structure: If you are trying to append a structure to a table, ensure that the append structure itself does not contain any reserved field names.
  
  Related Information:
  
  SAP Documentation: Check the official SAP documentation for guidelines on naming conventions and reserved names.
  ABAP Dictionary (SE11): Use transaction SE11 to explore the data dictionary and see existing fields and structures.
  SAP Notes: Look for relevant SAP Notes that might address specific issues related to this error message.
  Community Forums: Engage with SAP community forums or SAP support for additional insights and solutions from other developers who may have encountered similar issues.
  
  By following these steps, you should be able to resolve the NP231 error and successfully append your structure to the database table.