Normally, trailer cards of a given type are treated as one card and are counted together. Thus, the number of codes in a column for a particular trailer card contains the sum of all codes found in that column on all trailer cards of the given type (for example, all cards 2s).

However, you might prefer to produce holecounts on such cards based on their relative position in the group of trailer cards. For example, suppose card 2 is a trailer card and you want to make a holecount on the third card 2 of each group. The variable allread2 is true when a card 2 has been read in for the current record, and that it keeps count of the number of card 2s read. So, to produce a holecount for the third card 2, write:

You can also create filtered holecounts of trailer cards based on characteristics of the individual cards. Suppose you have a trailer card for each store visited, in which the store is identified in c79. The trailer card is the 5-card. Write: