Brief: Suppose you would like to get the object type code of the entity your are opening its form.
var currEntityObjTypeCode= Xrm.Page.context.getQueryStringParameters().etc;
- Type codes below 10,000 are reserved for OOB entities.
- Custom entities have a value greater than or equal to 10,000.
Note: Custom entity object type codes may change during import and are not guaranteed to be the same between systems.