Rodden rating — Astrology glossary

The Rodden rating is a system for classifying how reliable the birth-time data behind a chart is, devised by the astrologer Lois Rodden and used throughout the AstroDatabank collection. It assigns letter codes by source quality: AA for data from an official birth record, A from the person or family, B from a biography or autobiography, C for caution because the source is unverified, DD for dirty data where accounts conflict, and X or XX when the time is unknown or unobtainable. It matters because the value of any time-sensitive feature, such as the angles or house placements, depends entirely on the accuracy of the recorded moment, so the rating tells an astrologer how much weight to put on those parts of the chart. For example, a celebrity chart marked DD warns that its houses may be unreliable.