This template generates the (major) rank below the stated rank. Its original use is within Template:Automatic taxobox; given the rank of the taxon in question, it generates the ranks of the next subdivision. For instance, given "genus" it responds "Species"; given "subphylum" it responds "Class" (not "Superclass" or "Classis").
If a rank has not been listed in the template, it will return an error message. To fix this error, edit the template, listing the novel rank in the line before the equals preceding its child taxon. The syntax in the template ought to be self-explanatory.
Sub- and Super-ranks are not returned; it is expected that in most cases they can be listed alongside the taxon in question, as at Dinosaur.