The dark-knight tag reads as follows:
The Dark Knight is one the nicknames for the DC Comic superhero Batman and the name of a 2008 live action feature film. Also refered to as the Caped Crusader and the Darknight Detective, Batman is a founding member of the Justice League.
Based on this description I'm not sure what this tag is used for. Is it be supposed to a synonym for the the batman tag, or about the 2008 movie, The Dark Knight?
This edit changes too much in the original post; the original meaning or intent of the post would be lost
If it's supposed to be a synonym for the batman tag then it's currently lacking one. The synonym should be created, and a new tag for The Dark Knight needs to be created. Either way the tag should be edited to clearly state what it's intended to be used for. Having the additional information about other uses of the term in the excerpt is just confusing.