What kinds of changes need a JEP?

[mark.reinhold at oracle.com]

2017/11/7 8:46:14 -0800, brian.goetz at oracle.com:
> At the risk of being redundant, I’ll add that a JEP should be required for:
>  - Any language feature;
>  - Any change to the class file format.
> 
> While one could argue that these are subsumed by the other criteria,
> it is best to be explicit.

Good point.

Do you mean to allow changes to the language that are not "features"
to be done without a JEP?  In other words, why not say "any language
change"?

- Mark