Question: The 2011 Copa del Rey was a specific type of rivalry, given this name to any match between which groups?
Sentence (from "2011 Copa del Rey Final"): The match was a traditional 'El Clásico' rivalry between Barcelona and Real Madrid which took place on 20 April 2011 at the Mestalla Stadium, making it the sixth such Copa del Rey final (the last one was played also in Valencia on 5 April 1990), just four days after the two teams played each other in La Liga and seven days before they played each other in the UEFA Champions League first leg semi-final.
Relevant evidence: No