[RRFC] Add a field to package.json recommending that the package be unique.

Motivation ("The Why")

There can be a problem when multiple versions of a package in dependencies. but we generally find it difficult to issue warnings without false positives.

However, in the case of a package that uses a global store, such as React, multiple versions are not expected to be used at the same time in most cases. This often occurs as a runtime error and is a source of confusion.

Therefore, I think it would be better to add a field like recommendUnique: boolean that recommend such a package to be unique and issue a warning on any lint tools or npm ownself.

Example

package.json

{
  "recommendUnique": true
}

How

Current Behaviour

Desired Behaviour

$ some-linting-tool or npm install
[warn] `React` recommend unique version but detect multiple version. please run `npm ls` and solve it.

References

• Related React Issue: https://github.com/facebook/react/issues/13991

Start with the proposed package.json field and the referenced React issue, then review how npm install, npm ls, or linting tools could consume the recommendation. Before implementation, the RFC needs agreement on field semantics, warning ownership, and how multiple versions are detected; done means those behaviors are specified and accepted.