+ADVANCED USERS:-
+
+Once you are happy with the results you get, you may like to experiment.
+
+my example that filters hf/cw spots and accepts vhf/uhf spots from EU can be
+written with a mixed filter, eg:
+
+ rej/spot freq hf/cw
+ acc/spot freq 0/30000
+ acc/spot 2 freq 50000/1400000 and (by_zone 14,15,16 or call_zone 14,15,16)
+
+each filter slot actually has a 'reject' slot and an 'accept' slot. The reject
+slot is executed BEFORE the accept slot.
+
+It was mentioned earlier that after a reject test that doesn't match, the default
+for following tests is 'accept', the reverse is true for 'accept'. In the example
+what happens is that the reject is executed first, any non hf/cw spot is passed
+to the accept line, which lets thru everything else on HF.
+
+The next filter line lets through just VHF/UHF spots from EU.
+