COMMAND NAME:	qcodes

TYPE:		Data selection

SYNTAX:		"qcodes 5,6,789,DEF"
	    or  "qcodes 5-9 D-F"
	    or  "qcodes not 0-4 A-C"

DESCRIPTION:

Sets the quality code data selection input parameter.  Shown
in the example are three ways of establishing the quality code
filter "56789DEF".  You can specify codes directly, in any order,
separated by spaces, commas, or nothing at all.  You can also
specify ranges of quality codes from the sequence "ABCDEF0123456789"
by using the construction "2-8".  Preceding a specification by the
exact string "not" means take all except the specified codes.  This
information is applied as a filter by edit inputs, read, and plot.
Typing "qcodes" with no argument removes any limitation on quality
codes.