[tag:pin] is undefined, with 35 questions and many meanings:

 - Damaged pins on chips, connectors, etc.
 - Personal Identification Number
 - Connector configurations
 - Anchoring an application, folder, etc.
 - Deskpins

It's a candidate for cleanup.

There appears to be some commonality with [Poke a hole in "Pinning"](http://meta.superuser.com/questions/9674/poke-a-hole-in-pinning), which, like the weather, was talked about but not acted on.  Maybe both of these could get the official [meta-tag:status-planned] tag.