When you create or modify and object instance, the @Interfaces property in Web API v3 provides the ability to add or remove optional interfaces.
For example, the following payload can be used with a PATCH operation to add the ISDADocRevItems interface (true) and remove the IFDWDocRevItems interface (false) from an object.
{
"@Interfaces": {
"ISDADocRevItems": true,
"IFDWDocRevItems": false
}
}