Requirements

Ranked list

• A collection's ranked list can hold zero or more sources. A collection with at least one is a dictionary in this work's sense.
• Each new repository a reference points to is added to the ranked list automatically.
• Users can change the order.
• Users can add repositories the collection doesn't reference yet. This is how a collection points OCL to a source of equivalents, such as the implementation's own source, before anything references it.

Equivalency

• OCL checks equivalency in the sources, not only in the collection's own content (Rule 1).
• No equivalent duplicates: a dictionary can't contain both PIH:1065 Yes and CIEL:1065 Yes when they're SAME-AS mapped (Rule 2).
• When concepts are equivalent, the one from the highest-ranked source wins (Rule 2).
• How equivalency and cascading interact: the earlier document gave two orders, "apply equivalency, cascade, repeat" and "cascade, apply equivalency, repeat". Rule 3 restates the choice as whose answers and set members a replaced concept brings.

OpenMRS

• In the dictionary that OpenMRS imports, a question's answers and a set's members must be concepts the dictionary contains (Rule 4).

Milestones

1. The API: equivalency-aware expansion with ranked sources, tested against the Scenarios.
2. Authoring: checking equivalency when someone adds a reference. This is a separate problem from expansion, and harder for collections that expand automatically. Rule 6 is a start.