-# The element list is:-
-# 0 = frequency
-# 1 = call
-# 2 = date in unix format
-# 3 = comment
-# 4 = spotter
-# 5 = spotted dxcc country
-# 6 = spotter's dxcc country
-# 7 = origin
-# 8 = spotted itu
-# 9 = spotted cq
-# 10 = spotter's itu
-# 11 = spotter's cq
+# the elements of each list are
+#
+# [action, field_no, sort, possible_values, hops]
+#
+# where:-
+#
+# action is 1 or 0
+#
+# the field list is:-
+# 0 = frequency
+# 1 = call
+# 2 = date in unix format
+# 3 = comment
+# 4 = spotter
+# 5 = spotted dxcc country
+# 6 = spotter's dxcc country
+# 7 = origin
+# 8 = spotted itu
+# 9 = spotted cq
+# 10 = spotter's itu
+# 11 = spotter's cq
+# 12 = callsign of the channel on which the spot has appeared
+#
+# sort is
+# n - numeric list of numbers e.g. [ 1,2,3 ]
+# r - ranges of pairs of numbers e.g. between 2 and 4 or 10 to 17 - [ 2,4, 10,17 ]
+# a - an alphanumeric regex
+# d - the default rule
+#
+# if hops is left out or zero then the existing hop count will be used as normal