Comment 4 for bug 147668

Thanks for the report. This is an intentional result of our customisations to Yelp, which have been the subject of substantial discussion throughout the last two or three release cycles in the documentation team so for now I'm closing this bug as WONTFIX.

The topics currently available should cover most subjects relevant to the desktop user, and inside each topic it should be possible to browser to relevant manuals (and relevant index pages from upstream). The idea is to enable Ubuntu-created documents and upstream material to be merged into the structure rather than separate. Naturally, all the installed manuals are available from the search function as usual (which is where most users actually start).

If there are specific pages which you believe should be included in the current setup, and aren't, please file a bug on ubuntu-docs.