How to Remove Component Namespaces From the Proprietary Repository Namespace Confusion List

Note: This article is pertains to the Namespace Confusion Prevention (a.k.a. Dependency Confusion or Proprietary Repositories) feature introduced in Nexus Repo 3.30.0.
Official doc: https://help.sonatype.com/fw/preventing-namespace-confusion#PreventingNamespaceConfusion-RemovingComponentsfromtheNamespaceConfusionList

If you've enabled proprietary components by mistake for a hosted repository you can undo this via the following procedure.

First, you need to disable proprietary components. If this is not done, then the components will be re-added to the list, since there is an internal task that updates this list periodically.

You can disable this from each repository's config page by unchecking "Proprietary Components":

Or from the Proprietary Repositories page:

Next, obtain the "node-id" of the Nexus Repo instance. This can be found in the administration web UI under "support --> system information":

You'll also need the repository's ID, e.g. "maven-releases"

Finally, execute a DELETE REST API call against Nexus IQ Server resource "

You need to issue a DELETE request to the REST resource at "/repositories/{repositoryManageNodeId}/{repositoryId}/proprietary/names". 

For example:

curl -u username:password -v -X DELETE http://localhost:8070/rest/integration/repositories/3EFF78A1-5F819609-7BC13C89-B90B90DF-DEF32AD1/maven-releases/proprietary/names

The above call will return an HTTP 204 response if it succeeds.