Remember that the mysterious abbreviations (Latin) are in very old records. That era kept the records of nobility to track hereditary property and titular rights. Dying without male progeny would be documented if someone showed up claiming to be from a son later on. I'm sure the Latin explanation is right on. As for where people might record that in the records, like the others who have commented, I've seen the death field used for just about everything under the sun. I'd move it to the notes. Jerry