It's currently set as

 distributionType: type: string description: Unique identifier for the distribution type. 

Where examples include things like "zip", "tar.gz", "windows-x64.exe".

The problem - if we want to frame this as "unique identifier", this must be an enum. If we want to frame this as a free-form field describing packaging, that should be mentioned in the description and likely the field should be renamed. Right now, this is open to interpretation for publishers, and at the same time not clear how use that for clients - both of which things are not good.