Makes all keywords case insensitive (creates all keywords and calls all keywords lowercase.) Only works if you are using Base 36. Fixes disappearing capital letters.
Move the case-insensitive
folder into the /users/plugins
folder. Then, activate the plugin in the admin interface. That's all there is to it.
User must have YOURLS 1.5.1+ installed.
Works with YOURLS QR Code Plugin to generate smaller QR codes! This is because QR codes store upper-case characters significantly more efficiently than lower-case (ratio 5.5:8)
Borrowed code from Ozh's Force Lowercase plugin