I'm pretty sure that the tags pin and pins mean the same thing and should be merged. Are they synonyms of pinout? If not, they could use a tag wiki that explains the difference.
While we're on the subject of plurals, fuse and fuses should be merged. Since it is now impossible (except for moderators) to create tag names that look like singular/plural pairs (it wasn't when the site started), and that's the lot of them, this issue won't come up again.