3746353 - It's not possible to change custom field behavior for sales contracts related apps

There's the need to change the custom field behavior in apps related to sales contracts, for example, make a field read-only in the app 'Manage Sales Contracts - version 2', however the behavior option cannot be found in the app 'Custom Fields'.

For some data sources, the field behavior cannot be changed and contains the message: This usage does not support behavior. 

SAP S/4HANA Cloud Public Edition

Behavior definition is currently not available on key user apps for Manage Sales Contracts – Version 2, so setting a custom field to read-only via the Custom Fields app is not supported.

Changing the custom field behavior via the key user Custom Fields app is not supported at this time. As a workaround, use developer extensibility (ABAP RESTful Application Programming Model behavior extensions) to enforce the field as read-only at runtime. Refer to Extensibility-Enablement for Behavior Extensions | SAP Help Portal

Additionally, it's strongly advised to raise a feature request for this business requirement. This will inform the responsible development team as to what additional functionality should be considered for future releases. 

KBA 2963059 - How to Submit Feature Requests for SAP S/4HANA Cloud Product

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