Hierarchical labels don't cut it

Some systems have hiearchical labels.

E.g. Gmail - in some configurations Label/Sub appears to have label Label and sublabel Sub - but in reality it is just a label Label/Sub. And many tools that look at Gmail do not know about this hierarcjhy, so present the labels with / paths, flattened. Ugh.

Some tools allow labels to be applied to other labels.

E.g. Android app Folder Organizer (but not in free trial version, so Ihaven't tried).

E.g. Mediawiki categories can be applied to other categories.

This is better, but not quite there.

E.g. I may want to see a hierarchy MailingLists/Linux and Linux/MailingLists, but not all Linux stuff is related to mailing lists.  Most Linux stuff will be Computers/OS/Linux, but some Computers/OS/Linux/MailingList stuff may be purely social.

Put another way: there's a large amount of stuff that should be tagged Linux.  Some will be MailingList related, some not.  Some will be Computers/OS related, but some not.

I see tagging label relationships, such as hierarchies and paths and reflexive relationships, as being more suggestions.  When we tag an object, we may be asked which of the standard relations for that tag will apply.  We can accept default sggestions, or edit at any time.  After the fact, we can query using the relations stored with that object, or also with rel;atins stored with the Labels on that object that are not currently associated with that object - perhaps because you had not set them up when you tagged the object.

I see label relationships, such as hierarchies and paths and reflexive relationships, as being more related to browsing, choosing and selecting tags, and choosing and selecting objects.