1. The purpose of this function is to code each page of a document set with a number sequence running from 0 up to 15 and then restarting at 0 for the next document set. In the event that a document group exceeds 16 pages, then the numbering goes from 0 to 15, restarting at 0 and incrementing to the last page.This number sequence is printed on each page of a set or group, which is to be inserted into an envelope. Therefore, as soon as a loss of sequence is detected, it indicates an error in the page order and stops the machine so that the operator can rectify the fault. This ensures that integrity of document sets is maintained, and that each envelope is filled correctly. This function is achieved by programming up to four marks and printing them as a binary sequence as shown below.

2. Due to the fact that the forms may be fed ‘face up’ or ‘face down’ from the form stack on the machine infeed unit, it means that the forms may be processed either in the order they were printed, or the reverse order. However, the OMR system on the machine checks the numbering in a count up sequence. Additionally, if the forms are printed with no zero, for example, 1 to 15, then the checking system can be programmed to exclude zero from the number sequence.
3. The normal security system for ensuring that all the printed pages are processed correctly through the machine is Form Sequence within a Job (see Form Sequence within a Job). Form Sequence within a Group should only be considered when Form Sequence within a Job cannot be used.