If a printer supports an input tray selection mechanism, then the following options are recommended for use. Local conditions or printer type may require addition options.
inupper, inlower, intray1, intray2, ..., manual, envelope
The input tray selection options should start with the in prefix and correspond to the various trays, if possible. The manual and envelope options are included to select manual feed or envelope feed.
There is a possible source of conflict here as there may be an envelope feeder as well as an envelope media. This is a printer specific dependency.
source=name
The key=value entry allows users to use options such as -Zsource=inbin1, which may be useful for systems that have an unusual or nonstandard input selection mechanism.