This ECMA Standard specifies fine-grain extensions to PCTE, as defined in Standard ECMA-149.
The extensions described in this Standard are as follows:
For some operations specified in ECMA-149, the semantics is extended for the cases when the objects manipulated by these operations are fine-grain objects. Some operations have their semantics affected because new errors may occur.
There are new operations.
There are new errors.
When objects passed as arguments of PCTE operations are not fine-grain objects, the syntax and semantics of the operations described in this Standard are the same as the syntax and semantics of operations described in ECMA-149.
For this reason, this Standard is said to be upwards compatible from ECMA-149.