Referential integrity is assured for all relationship forms via tombstones. Referential integrity is assured by only deleting objects when all references to that object have been removed. A.1.2.2 Composite Objects Supports equality operations across composite objects. Supports copy operations across composite objects. Supports delete operations across composite objects.
Supports lock operations across composite objects.
An object anywhere in the database may be accessed. The syntactic structure used to reference an object is not dependent upon the object's location. An object can be programmatically moved to a new location within the database. A.1.2.4 Object Versioning Supports a linear versioning policy. Supports a branch versioning policy.