Useful : Intune: Third-Party ADMX & OMA-URI – Step-by-Step (Part 3) (sifr.ca)

This CSP contains ADMX-backed policies which require a special SyncML format to enable or disable. You must specify the data type in the SyncML as <Format>chr</Format>. For details, see Understanding ADMX-backed policies.

The payload of the SyncML must be XML-encoded; for this XML encoding, there are a variety of online encoders that you can use. To avoid encoding the payload, you can use CDATA if your MDM supports it. For more information, see CDATA Sections.

This is an ADMX-backed policy and requires SyncML format for configuration. For an example of SyncML format, refer to Enabling a policy.

OMA-URI

./User/Vendor/MSFT/Policy/Config/ADMX_Explorer/PreventItemCreationInUsersFilesFolder

Value ( String )

<enabled/><data id="PreventItemCreationInUsersFilesFolder" value="1"/>