If you enter "cpoison", "cinstant damage", "cweakness" or "cslowness" into the creative search, it will return the potions with the relative effects. I cannot find any other potions to do this with any other letter. (Obviously need only a fraction of the potion name to see the faulty results.)
MC-29431
Search function returns some extra potion results
Resolved
Fixed
2
Confirmed
display-Name, potion, search
Minecraft 1.6.2, Minecraft 13w36b, Minecraft 13w37a, Minecraft 13w42b, Minecraft 13w43a, ..., Minecraft 14w28b, Minecraft 14w29b, Minecraft 14w30b, Minecraft 14w30c, Minecraft 14w31a
Minecraft 14w32a
Retrieved
Confirmed in version 1.7.2 with the said potions.