To identify discontinuations in column 2, users need to start from the last row (position 80) in column 1 and keep looking up until they found that a method changed. In the same position in column 2 of the last month of use there should be a code indicating the reason for discontinuation. To illustrate the problem let me put columns 1 and 2 aligned on top of each other.

LLBPPPPPPPP000LLLLLLLLLLLLLLLLLLLLLLLLLLBPPPPPPPP0099LLLLLLLLLLLLLLBPPP
              2                                    2 8

In the example above the respondent started using method L in position 76 (5th month from the bottom of the calendar) in column 1. The respondent used the method for 14 months and changed to method 9, she gave code 8 as the reason for discontinuation. In position 63 (which corresponds to the last month of use of method L), the discontinuation code is recorded in column 2. The respondent then used method 9 for two months and discontinued for reason 2, and so on.

Users need to be aware that chronologically the first month of the calendar correspond to the last position in column 1. Or to put in another way, position 80 of column 1 correspond to the first month where calendar data is collected. That first position correspond to the CMC code given by variable V017.