Data can be of varying
qualities. This field allows requesters to specify the quality of the data
they want to receive. The default value is B (for best available). The values
the Quality Field can assume are:
B Best Data (Q,if not Q then D, if not Q or D then R)
E Everything (Q & D & R)
Q Data tagged as QC'd
D Data of indeterminate quality
(Before June 2002 all miniSEED data was labeled D and as such
some had been quality controlled and some had not.)
R Raw Data
(For example, data reaching the IRIS DMC via real-time telemetric
methods does not have QC applied and is labeled R beginning with
data in the year 2002.)