This kind of ticket was in use until +/- 1991.
There were 2 types, with the same print: the green tickets (slightly more expensive) were for transit journeys and the white ones for journeys without a transit.
However, there were some historical or temporary exceptions, e.g. due to works.
Depending on the circumstances, the driver (there were no receivers anymore for a long time) with the right pencil color (blue or red depending on the direction) had to indicate one or more numbers. The highest line number at that time was line 38, but the numbers were also used to indicate the hour in case of a transfer. On the changing vehicle, a corner of the ticket was cut off...