Symbol LS 9100 Product Reference Manual page 116

Parameters
T wo Discrete Lengths
This option allows you to decode only those codes containing
two selected lengths. For example, if you select Code 39 Two
Discrete Lengths, then scan 0, 2, 1, 4, only Code 39 symbols
containing 2 or 14 characters are decoded. Numeric Bar Codes
begin on page 5-160. If you make a mistake, scan CANCEL on
page 5-170.
Note: Selecting this option disables Code 39
Decode Performance.
CODE 39 - TWO DISCRETE LENGTHS
5-67