(these are my current amended comments - first one is new and the others are from the November F2F...)
MS1: No attribute specifying the number of materials that are supported; propose adding "materials-col-values-supported (integer(1:MAX))" Printer Description attribute.
MS2: (November 2016 F2F feedback) What about tolerances for material-diameter? Useful for controlling output quality since large tolerances can lead to less accurate printing (printer extrudes a volume of material by advancing a length of filament - actual volume depends on diameter of filament that was extruded...) Propose adding new "material-diameter-tolerance (integer(0:MAX))" member attribute for "materials-col" to define the tolerance of the loaded/preset/requested material in nanometers.
MS3: (November 2016 F2F feedback): "job-constraints-supported" and "job-resolvers-supported" are currently required but a printer may not have any constraints - needs to be removed from Table 5.
Michael Sweet, Senior Printing System Engineer