feat(profiles): add interoperability req for review process

ethanresnick · ethanresnick · commit fbfa7f85345c · 2018-12-19T14:56:11.000-08:00
diff --git a/extensions/index.md b/extensions/index.md
@@ -80,8 +80,9 @@ To register your profile:
    out template as the `index.md` file in that directory folder. (See [an example](https://github.com/json-api/json-api/tree/gh-pages/_profiles/ethanresnick/cursor-pagination).)
 
 Once submitted, one of JSON:API's editors will review your profile to check that
-it: 1) follows the template above; 2) complies with JSON:API's [requirements for profiles](/format/1.1/#profiles-authoring);
-and 3) wouldn't cause any problems were it to become widely adopted. If your
+it: 1) follows the template above; 2) is specified precisely enough to enable 
+interoperable implementations; 3) complies with JSON:API's [requirements for profiles](/format/1.1/#profiles-authoring);
+and 4) wouldn't cause any problems were it to become widely adopted. If your
 profile meets these three criteria, it will generally be **approved within a week**.
 
 In limited cases (e.g., if your profile defines a new, fundamental mechanism for
