Find a better name for "Extra Deployments"

During reviews of the feature it happened multiple times that people mentioned that they had difficulty understanding what an "Extra Deployment" is (aka deployments with a path prefix). In addition I see myself explaining it in various places ahead of those questions. This signals to me that "Extra Deployment" isn't a good name for the feature and we should try to find a better one ahead of beta.

Suggestions

I think there are two more fitting alternatives:

• Environment Deployment: It conveys that this should be used to have other environments, such as staging, or review environments. I don't like that it would confuse the functionality with Environments, something that we purposely refrained from integrating pages with.
• Secondary Deployment: My preferred name. It suggests that it's somehow different from the main deployment, but it can still be a fully qualified deployment (e.g. a documentation website for an earlier version of the documented software is available at /v2)

Notes

I'd like to refrain from using the word "prefix", because I can see the functionality moving to subdomains in the future.