Each time an ordinary record or set of cards comprising a multicard record is read in, that data is processed first by the edit section and then by the tabulation section of your program. The complete record is edited and tabulated in one go. The exception to this is the trailer card record where processing can take place a number of times within each record for each lower level.

To ensure that only the part of the edit section applying to a particular level is used, the edit section is defined separately for each level. Similarly, the table instructions specify the level at which the table should be incremented. For more information about levels, see Dealing with hierarchical data.