Usage notes

If MPP or RM is set lower than the actual LPD line length, the full width is not used. If they are set greater than the actual LPD line length, then LPD either truncates the long lines (losing data) or splits the lines and disrupts the vertical spacing of the file.
If BM is set to 1, NPF inserts no automatic form feeds. Explicit form feed or Select Vertical Channel 1 in the data stream cause form feeds. If BM is greater than 1, NPF moves lines that might print below BM to TM on the next page.
The Network Print Facility assumes LPD starts each file at the top of a new page. The Network Print Facility also assumes that form feed causes LPD to position at line 1 of the next page, so the Network Print Facility inserts blank lines at the top of each page whenever the top margin is greater than 1. MPL should be the total number of print lines on the page. For correct formatting, the number of printable lines ((BM + 1) -TM) needs to be correct. If this number is too small, the full page length is not used. If it is too large, LPD prints over the page or inserts additional form feeds.
The SCS presentation position command permits printing outside of the margins but within the physical page dimensions. If your application is using SCS PP, then all margin settings must be consistent with LPD.