|data.certainty defines the range of attribute values expressing a degree of certainty.|
|Module||tei — The TEI Infrastructure|
data.certainty = "high" | "medium" | "low" | "unknown"
Certainty may be expressed by one of the predefined symbolic values high, medium, or low. The value unknown should be used in cases where the encoder does not wish to assert an opinion about the matter. For more precise indication, data.probability may be used instead or in addition.