Update fp-012-naming-conventions.md (#2891)

* Update fp-012-naming-conventions.md

* Update principles/fp-012-naming-conventions.md

Co-authored-by: Nomi Harris <nlharris@users.noreply.github.com>

---------

Co-authored-by: Nomi Harris <nlharris@users.noreply.github.com>

Author: nataled

principles/fp-012-naming-conventions.md

@@ -12,31 +12,39 @@ GO TO: [Recommendations/Requirements](#recommendations-and-requirements) |
 
 ## Summary
 
-The names (primary labels) for elements (classes, properties, etc.) in an ontology SHOULD be unique among OBO Foundry ontologies, and MUST be unique within its own ontology.
+The names (primary labels) for elements (classes, properties, etc.) in an ontology SHOULD be unique among OBO Foundry ontologies, MUST be unique within its own ontology, and SHOULD be written in accepted format.
 
 ## Purpose
 
-Text to be added.
+Primary labels are a major mechanism by which terms are referenced. Accordingly, it is important that labels be unique, unambiguous, and formatted for ease of reading and comprehension. Non-unique labels (sometimes for terms that mean very different things) may cause confusion for human users and may prevent some ontology editing tools from full access to terms (for example, when crafting axioms). Labels that are ambiguous cause difficulty when users are trying to identify a term that matches their intention.
 
 ## Recommendations and Requirements
 
 Text to be added.
+
 For full details, see this paper: <http://www.biomedcentral.com/1471-2105/10/125>
 
 Briefly, some important things to remember:
 
-- use rdfs:label for the primary label
-- include exactly one rdfs:label for every declared entity (e.g. class, property)
-- write labels, synonyms, etc as if writing in plain English text. ie use spaces to separate words, only capitalize proper names (e.g. Parkinson disease). Do not use CamelCase, do_not_use_underscores
-- avoid extra spaces between words, or at the beginning or end of the term label
-- spell out abbreviations. Abbreviations can be included as a separate property.
-- make the primary labels to be as unambiguous as possible. Remember, your ontology may be used in a different context than that for which it was originally intended. Remember also of course that the label should be unambiguous without looking at parent terms
-- labels MUST be unique within an ontology
-- use the IAO property 'obo foundry unique label' [http://purl.obolibrary.org/obo/IAO_0000589](http://purl.obolibrary.org/obo/IAO_0000589) to declare a pan-OBO unique label if required
+- There MUST be exactly one rdfs:label for every declared entity (e.g. class, property)
+- Labels MUST be unique within an ontology and SHOULD be unique within the wider OBO Foundry
+- Format requirements
+  - Write labels and synonyms using plain English text
+    - Use spaces to separate words
+    - Only capitalize proper names (e.g. Parkinson disease)
+    - Do not use CamelCase
+    - Do not use under_scores
+  - Avoid extra spaces between words, or at the beginning or end of the term label
+  - Spell out abbreviations. Abbreviations can be included as alternative labels (i.e., synonyms)
+- Primary labels SHOULD be as unambiguous as possible. An ontology may be used in a context that differs from that for which it was originally intended, including being combined with other ontologies.
+- Optimally, each label SHOULD be unambiguous even without looking at parent terms
 
 ## Implementation
 
 Text to be added.
+- Use rdfs:label for the primary label
+- use the IAO property 'obo foundry unique label' [http://purl.obolibrary.org/obo/IAO_0000589](http://purl.obolibrary.org/obo/IAO_0000589) to declare a pan-OBO unique label if required
+
 
 ## Examples