A boolean valued attribute to indicate that a sample assessment is eligible to be discounted (discountable=true) from annual Compliance Assessments. This attribute is updated throughout the season, and is required to show where a sample meets the criteria to be eligible for discounting. The absence of a value for this attribute indicates that a judgment on whether the sample is discountable is pending. This may occur several days after first publication of sample assessment result.
An boolean valued attribute on a discountable :SampleAssessment which indicates that it has been discounted (discounted=true) for use in annual Compliance Assessments. This attribute may be present on a discountable sample assessment. It reflects a descision made at the end of the season in which the sample was taken as to whether to actually discount (discounted=true) a discountable sample assessment from annual Compliance Assessments.
A class of Step Change events, generally improvements that mark a step change water quality such that it is no longer appropriate to include samples taken prior to the step change in on-going annual compliance assessments