Trees/hierarchies ("folders") are for organization, unconstrained graphs/networks ("tags") are for ontologies. Crossing these streams leads to a lot of trouble. When flexible graphs/networks are abused for organizational purposes, you get circular dependencies, spaghetti code, and general dysfunction. Organizations (code or people) need to be easy to navigate. When rigid hierarchies are abused for classification purp…
An interesting hybrid approach I've experimented with in the past is to use tags while ensuring that the tags themselves are purely hierarchical. (Is there a name for this scheme?)
Can you elaborate?