Pset_Uncertainty Property set capturing the geometric uncertainty regarding measurements including how the way that uncertainty was assessed. IfcProduct IfcProduct UncertaintyBasis Indication of the basis of the uncertainty MEASUREMENT OBSERVATION ASSESSMENT INTERPRETATION ESTIMATE USERDEFINED NOTKNOWN NOTDEFINED MEASUREMENT OBSERVATION ASSESSMENT INTERPRETATION ESTIMATE USERDEFINED User Defined NOTKNOWN Value is unkown (unknown) Value is unknown. NOTDEFINED Notdefined UncertaintyDescription General description of the uncertainty associated to the element or feature, its source and implications. HorizontalUncertainty Indicative (95%-100%) range diameter associated to the vertical shape and position in X, if different to the linear uncertainty. LinearUncertainty Indicative (95%-100%) range diameter associated to the overall shape and position in XYZ. OrthogonalUncertainty Indicative (95%-100%) range diameter associated to the horizontal shape and position in Y, if different to the horizontal uncertainty. VerticalUncertainty Indicative (95%-100%) range diameter associated to the vertical shape and position in Z, if different to the linear uncertainty.