YaCy as a "Search Engine for Projects" and/or "Topic-Oriented Search"

In my search for information about YaCy I came across this page:

https://wn.com/yacy/wikipedia

Which includes this statement:

YaCy as a Search Appliance:Topic-Oriented Search and Search Engine for Projects

Some means of consolidating diverse websites, or being able to search for content related to the same project or research topic, that do not necessarily have active links between them, seems like an important function to me and something that could be possible, perhaps by adding some metadata in the form of a “project key” to the various related sites.

I’m not entirely sure what functionality the above quotation is referring to or how to implement it.

The ideas of “Topic-Oriented Search” and “Search Engine for Projects” seems similar to or related to the idea of “conceptual indexing”.

Anyway, I’m a little lost. This sounds fantastic but I don’t have much of a clue how it might work in YaCy, or what specifically this reference is talking about.

How can a “Topic-Oriented Search” as decribed in this reference be implemented in YaCy?

To, I think, answer my own question, after watching the video here:

The “Search Engine for Projects” refers to a more controlled situation where a YaCy instance is used exclusively for a particular project where a project might have a wiki page, a forum, a blog, a content management system each with its own separate search engine. YaCy could be used to simplify that kind of situation.

What I had in mind was a means of doing that for all open collaborative projects across the entire internet, which would involve all related project pages using the same “project key” in their metadata string, which would allow any search engine to associate the pages.