http://y6gnjkv2xrjfb7qgs3kmsfyw5qwe7avjvvrnh7wpz5hvtrocm4rbetid.onion
You can also assign names like you would do with git branches with bookmarks, but I do not use them often. Part of my confusion is also due to hg log listing in chronological order (I believe, but I am still unsure). It starts from the most recent commit it knows and then shows commits that are not ancestors of the one checked out.