Darksin tag not searchable.

Short explanation:
https://www.fakku.net/manga/tags/darkskin - works

https://www.fakku.net/search/darkskin - "Your search did not return any results."

other tags, such as pettanko, are working perfectly both ways.

Hmm... seems like the actual term one needs to use in searches is "dark skin", with a space in it.