The bandpass in which the measurement is made must be identified.
The bandpass name is recorded in a column labelled BAND.
(This name, combined with the information in the instrument file, is used to
identify the detector in multichannel instruments.)
Standard passband names should be used:
'V', 'B', 'U', 'URL', 'R', 'I', 'u', 'v', 'b', 'y', 'betaW', etc.
These should agree with the notation used for standard indices for the
standard stars (see section 
, above, which
describes standard-star table files).
Standard band names are also listed in subsection ,
``Passbands''.
For DARK measurements, a digit must be appended to indicate the detector number, if more than one detector is used: DARK1, DARK2, etc. If red leaks are measured for two or more passbands, they must be plainly marked; e.g., 'URL', 'BRL', etc. If ``neutral'' filters are used to measure nonlinearity, as is often done with pulse-counting systems, the appropriate suffix 'ND' (for a single attenuator), or 'ND1', 'ND2', etc., should be appended to the BAND value.
Often a filter position is carried in the original data as a code. Such information must be decoded to a standard band name in the observation-table file. The decoding information is normally found in the instrumental table file.