Add identifier review to SOP (#2394)

Co-authored-by: Paul Fabry <[email protected]>

Author: matentzn

docs/SOP.md

@@ -36,7 +36,9 @@ The goal of this SOP is to provide a clear set of criteria to be checked for the
 
 Check the following and provide a brief summary in the tracker issue for the new ontology request. All items of feedback must be provided using GitHub checklist syntax (`- [ ] TODO`) in order to track how far along they are in being addressed. Addressable issues identified as part of the review should be added to the new ontology’s issue tracker.
 1. Ontology scope. The new ontology must present use cases demonstrating its relevance to the life sciences.  Was the ontology developed using expert input or trusted scientific sources representative of the consensus in its target domain of knowledge? If the ontology was developed for a very specific purpose or community, representation and consensus need not be broad; however, this scope should be clearly stated.
-2. Terms with the new ontology prefix. There MUST NOT be a term with the same meaning available in another OBO Foundry ontology, ie there must not be a term referring to a concept that already exists in another OBO Foundry ontology (whether or not the label is identical). There SHOULD NOT be another OBO Foundry ontology whose scope covers any of the new terms. In the event that these conditions cannot be fulfilled, justification(s) MUST be provided. Such justification(s) include:
+2. Terms with the new ontology prefix. 
+All new terms MUST follow the [OBO identifier scheme](http://obofoundry.org/id-policy) (often they are accidentally written wrongly, e.g. using https instead of http). 
+There MUST NOT be a term with the same meaning available in another OBO Foundry ontology, ie there must not be a term referring to a concept that already exists in another OBO Foundry ontology (whether or not the label is identical). There SHOULD NOT be another OBO Foundry ontology whose scope covers any of the new terms. In the event that these conditions cannot be fulfilled, justification(s) MUST be provided. Such justification(s) include:
     - the demonstration that these terms are actually not the same (this happens when term meaning/concept is ambiguous); or
     - the other OBO Foundry ontology (for which the terms were in scope) was contacted and rejected the request for adding new terms in scope for that ontology.
 3. Correct use of imported terms. Does the ontology accurately reuse terms from other OBO ontologies?