b997eee8_CCG___What_s_That_Inside_Joke___In_joke
[Card] Appropriate Garb [Exp.] AW [Type] Ref [In-joke] 
The 6th Doctor can't use it because his clothes were always outrageous and inappropriate. Because the 5th Doctor and companions almost never wore anything other than their costume for the season, they also can't use (destroy) this Artifact.
Unauthorized Dr. Who CCG - What's That Inside Joke?
In-joke