CLIC\IGNORE list_of_observations
This command can be used to declare the specified list of Observations
(from the input file) to be ignored in all FIND operations. They effec-
tively become invisible to CLIC (except in a LIST IN command), until a
FILE IN command is typed again. The input file is not physically modi-
fied however. The list of observation can be given using the same for-
mat as with a FOR command (e.g. n1 n2 n3 TO n4 BY n5 n6 TO n7).