Merge branch 'master' into patch-1

Author: nataled

docs/PrinciplesReviewWorkflow.md

@@ -18,5 +18,6 @@ For the following, steps 1-5 are internal to the EWG and steps 6-7 are internal
 9. Allow a two-week commenting period on the pull request.
 10. If the feedback includes major changes or objections, re-discuss during an OBO Operations call and re-do any relevant steps indicated above.
 11. At the end of the commenting period, assuming no major changes are needed, a member of the EWG will merge the pull request (removing 'draft' status if appropriate) and thereby make the changes public.
+12. Add the new principle to the [Principles Summary](https://github.com/OBOFoundry/OBOFoundry.github.io/blob/master/principles/fp-000-summary.md) list and to the [Principles dropdown menu](https://github.com/OBOFoundry/OBOFoundry.github.io/blob/master/principles/all.yml).
 
 The need for a new principle can arise when an existing principle tries to cover too much and requires splitting, or as new needs arise within the community.

principles/all.yml

@@ -44,6 +44,9 @@ principles:
 - id: fp-016-maintenance
   layout: principle
   title: Maintenance (principle 16)
+- id: fp-019-term-stability
+  layout: principle
+  title: Stability (principle 19)
 - id: fp-020-responsiveness
   layout: principle
   title: Responsiveness (principle 20)

principles/fp-000-summary.md

@@ -40,4 +40,6 @@ P13) <b>Notification of Changes</b> - Ontologies SHOULD announce major changes t
 
 P16) <b>Maintenance</b> - The ontology needs to reflect changes in scientific consensus to remain accurate over time.
 
+P19) <b>Term Stability</b> - The definition of a term MUST always denote the same thing(s)–known as “referent(s)”–in reality. If a proposed change to the definition would substantially change its referents, then a new term with new IRI and definition MUST instead be created.
+
 P20) <b>Responsiveness</b> - Ontology developers MUST offer channels for community participation and SHOULD be responsive to requests.