I noticed three jack_harness* tags:
1) jack_harkness
2) jack_harkness_(character)
3) jack_harkness_(mlp)
(all three are character tags)
Only two posts are of the human Jack Harness (from Doctor Who),
the rest are pony versions of Jack Harkness (checked MLP wikis and apparently not an official MLP character).
question 1: Tag pony-versions with jack_harness AND jack_harkness_(mlp) ?
question 2: retag jack_harkness_(character) posts (both human) as jack_harkness?
Updated