JES2 supports the 3211 indexing feature in two ways:

The system supplies two special FCBs: FCB26 for 6 lines per inch and FCB28 for 8 lines per inch (specified as FCB=6 and FCB=8, respectively). These FCBs contain a channel 1 indication in position 1, a special index flag in the third byte, and the number of lines per inch in the fourth byte of the image.

The special index flag in the third byte of FCB26 and FCB28 contains X'80' plus a binary index value, in the range 1 to 32 (default=1). The index value sets the left margin (1 indicates flush-left; other values cause indentation of the print line by N-1 positions).

If JES2 is to use any other FCB images, the images must specify channel 1 in position 1; otherwise, JES2 positions the forms in the printer incorrectly. (Because STD1 and STD2 do not specify channel 1 in position 1, they must be modified for JES2.)

If the third byte of any other FCB image (specifying the number of lines per inch) contains a data character other than X'80', JES2 uses that specification and supplies an index value of 1.

JES3 does not support the 3211 indexing feature, and any indexing commands from JES3 are ignored by the 3203 Model 5.