Imagine a folksonomy for private tags.
Folksonomies allow an ecosystem of users to discover emergent ontologies in a bottom-up, crowd-sourced way.
For example, Flickr allows anyone to tag a photo with whatever they want.
But as they attach a tag, it shows them the other similar tags, sorted by popularity.
You might plan to attach #BeachLife but see that #DayAtTheBeach has 10x the use, and use that instead.
This allows the community to emergently discover schelling points.
But that doesn't work in private contexts.
If I create a new label in Gmail, I can't draw on the wisdom of the crowd on what a good ontology is.
Imagine if when creating a new private tag, if you had filtered past having any of your own tags, you could see tags the community uses that overlaps?