lpsched

lpsched://localhost/printers/queue

This printer URI scheme can only be used to contact a local LP service to access the print queue that is specified in the URI. 

lpd

lpd://localhost/printers/queue[#extensions]

Use this printer URI scheme to contact local or remote print services to address the specified print queue on the host that is specified in the URI. The optional #extensions can be specified as #solaris to indicate that the server host will process Solaris extensions to the RFC-1179 protocol during print job submission.

ipp

ipp://server[:port]/printers/queue

http://server:631/printers/queue

ipp://server[:port]/...

Use this printer URI scheme to contact local or remote print services to address a particular print queue on the host that is specified in the URI. The IPP URI scheme is described in the IPP specifications. This printer URI scheme utilizes more of a free form than the LPD printer URI scheme. All of the Solaris and CUPS-based print queues are accessed by using these schemes, or formats. Access to print queues on other IPP-based print servers requires the use of the server supported IPP URI scheme. Typically, the scheme that is used is one those that are listed in this table.