From LDS HelpPNA (Personal Name Authority)
Contains a personal or family name used as the main entry for a collection.
100a Tuttle, Albert Theodore d 1919-1986 100a Savage, Charles Roscoe d 1832-1909 100a Wilson family (This type of authority should only be used when no other information can be determined about a family)
The following are examples of the different kinds of dates used on personal names:
100a Smith, John Living person d 1924- 100a Smith, John Both years known d 1837-1896 100a Smith, John Probable year of birth d 1837?-1896 100a Smith, John Year of birth uncertain by several years d ca. 1837-1896 100a Smith, John Approximate year of death d 1837 ca. 1896 100a Smith, John Both years approximate d ca. 1837-ca. 1896 100a Smith, John Year of death unknown, person is probably not living d b. 1825 100a Smith, John Year of birth unknown d d. 1859 100a Smith, John Neither birth or death known, but the person is known to have been alive (flourished) during this date. d fl. 1845