Cancelling an electrode.
An electrode can be cancelled (that is, ignored) by putting 0 subdivisions. The rest of the electrode data then remains in the data file, for later re-use.
Before this line that gives 0 subdivisions is reached the electrode data is tested in the usual way, and so if a test fails the program will stop.
Also note that in some of the messages about electrodes the number of an electrode might refer to its position in the original list (before cancellation).