PARVQ (Parameter Qualifier)

Attribute Format Table Guidelines & Restrictions Definition
C2 Valid Values      RESULTS PARVQ cannot be left blank. The code indicates the Qualifier of an analytical result, or identifies a special type of parameter, such as a surrogate.
PARVQ must contain a valid value.
Special Notes
The PARVQ field may be used in several ways. The field is most commonly used to qualify results. Standard analytical results will be qualified with "=" or "ND" ("Not Detected"). The PARVQ field may also be used to identify a special type of parameter such as a tentatively identified compound ("TI"), surrogates ("SU"), or internal standards ("IN"). And lastly, the PARVQ field may be used to indicate that data is not usable for a given parameter, such as "NR" ("Not Reported").