4.3.3 Track information common-block /ZATRS/ :

On lines 1 to MTRK of each of the variables, ZATRS contains all the info on each track seen by the detector. On the following lines (ie. MTRK+1 to TTRK), info on tracks not seen by the detector are given. Hence, looping from line 1 to MTRK covers all seen particles, with no 'holes', and looping true values all the way to TTRK covers all particles generated by the event simulation. When applicable, the last index is used to indicate either TRUe values or SEEN ones. Note that there might be SEEN values also for tracks on lines after MTRK. This is because a track might have been rejected after detector-response was simulated, by a call to ZDEFFI. Always use the variable TRACK as a pointer in this common-block (as loop index or otherwise).