To enable effective querying of the ballad databases I have had to assign each ballad a unique, arbitrarily "standardized" title and a totally arbitrary, but unique number, because only in this way can all the versions of any particular ballad be identified. However, these conventions are not meant to suggest that the numbers and titles used herein are in any way more valid or constitute any sort of improvement over numerous other conventions developed by others to identify and catalog the poetic materials of the Pan-Hispanic Ballad tradition. Because of my years of collaboration with the Seminary Menéndez Pidal, where I designed the first electronic databases for the ballad projects of the eighties and early nineties, it has been convenient for me in the current project to use--where available--the same numbers, keys and titles as those in use at the SMP since 1980.