Birth and death dates
- Bet: yyyy-yyyy. Indicates a date between those years.
- Abt: yyyy or mm-yyyy. Indicates a date near a year or month and year.
- Aft: yyyy. After a year.
- Bef: yyyy. Before a year.
- Knw: mm-dd-yyyy. Indicates a known month, day, and year.
- Year: yyyy. Indicates a known year, but not the day or month.