1000 documents per submission maximum (each document may contain multiple pages)
One and only one XML file in ZIP archive (name it whatever you like, but make sure it has .XML extension).
The only other files that may be present are TIFF files (.tif is the preferred extension, but .tiff is allowed).
TIFF4 Format (aka TIFF using 'CCITT Group 4 Fax' compression)
Fill Order must be 'Most Significant Bit (MSB) to Least Significant Bit (LSB)'
'Single strip' images only.
No tiled images allowed.
Black and White only (color depth: 1 bit)
One image per file (no multi-page TIFF files allowed; A duplex document should be converted to two image files)