Fldigi
supports a generic but robust set of contest functions. In
addition to serial-in and serial-out you can capture and transmit three
exchange sequences unique to a specific contest. Enter the
exchange you want to send for each of the three. You can force
the RST in/out to always be 599. That seems to be a norm for many
contests. When operating in a CW contest you can have fldigi send
cut numbers, T for 0, N for nine.
The serial number can be set
to use leading zeros. You can specifiy the starting number for
the sequence and how many digits are sent, ie: 0024. Pressing
Reset will set the starting number to the qso logging serial out field.
See
Contest How To for more info.
You can check for duplicates
by any combination of the specified named fields. You can also
specify that the duplicate had to occur with a given time interval.
Some VHF contests allow a duplicate CALL after a given time
interval.