One question I regularly get from implementors is how to handle so-called "multi-purpose trays" which can function both as a tiny paper tray and as the manual feed source. The question comes up because you don't report manually fed media in "media-col-ready" or "media-ready", but for these trays you can actually load media and tell the printer (via the built-in console) what media was loaded, just as if it was a dedicated paper tray.
My guidance has been the following:
1. The 'manual-feed' value of "media-source" requests that the Printer pause for user interaction (to insert the requested media) while 'by-pass-tray' requests that the Printer immediately print using the media from that source (pausing only when the tray is empty or loaded with a different media).
2. Implementations should report two values in the "media-source-supported" Printer Description attribute for so-called multi-purpose trays: 'manual-feed' and 'by-pass-tray'.
3. Likewise, implementations should report two values in the "printer-input-tray" Printer Description attribute, with "type=sheetFeedManual" for the 'manual-feed' source and "type=sheetFeedAutoRemovableTray" or "type=sheetFeedAutoNonRemovableTray" for the 'by-pass-tray' source, as applicable.
If there is consensus on this approach, I can write up a (short!) tech brief that we can publish to make it "official", and I can then point people to it...
(this should probably be more clearly specified in JPS3, but I have neither the time nor energy to tackle updating *that* document right now... :)
Michael Sweet, Senior Printing System Engineer