465   Missing identity constraints in IED section

This tissue has following status: green

Proposer: Christian Frei , ABB Switzerland

Page:

Clause: 9.3

Paragraph:

Category: Issue for edition 2 of this part

Issue: Currently, the SCL schema permits the following:
- two DOI with same name in the same tLN.
- two SDI/DAI with same name in the same tDOI
- two SDI/DAI with same name in the same tSDI

This should not be allowed, like it is in the DataTypeTemplates section.

Proposal: Add the following uniqueness identity constraints:
- Within an tLN, there cannot be two DOI with same name
- Within an tDOI, there cannot be two SDI/DAI with same name
- Within an tSDI, there cannot be two SDI/DAI with same name.

Advantages:
- no change to the semantics
- it would allow more error checking at schema level
- it eases the evaluation, if you know that if you are on a certain DO level, that you get all entries below this level.
- Another advantage is that it would make (some - those that would not be backward compatible) files smaller

Disadvantage: breaks backward compatibility.