1 This implies that the other two sides are of equal length, and that the diagonals are of equal length. 2  An alternative definition is: a quadrilateral with an axis of symmetry bisecting one pair of opposite sides. 3  Trapezium (NAm.): no sides are parallel.
An enumeration date commonly refers to the official or control date set for a particular enumeration event such as a census. The official enumeration date may vary from one enumeration to the next. The enumeration date is a control function for collecting data over a broad space of time. All data collected is based on its validity as of a single date, no matter what date the information is taken within the enumeration period.
The NPI is a ten-digit number (nine digits plus a check digit to detect keying errors.) It is simply a random number that never expires. It contains no information about the provider, such as state of residence or license number. The National Plan and Provider Enumeration System (NPPES) issue NPIs. The federal government is also responsible for assisting providers in completing the application and resolving problems associated with an NPI.