Q.Can I print an A4 document on the department printers?

A.A4 is a European standard paper size. It is typically found in documents coming from a European university or colleague. The paper size information is embedded in the postscript file.To verify the papersize you can use:

grep -i papersize <documentname.ps> and you will see something like this:
%%BeginPaperSize: a4

If you send an A4 sized document to a department printer, only the first page will print on its own. After that you need to be physically stationed at the printer to press "Shift-Continue" between each page. If you are not there, the printer will stall after the first page and your colleagues jobs will back up behind yours. In order to avoid this unhappy scenario, use the psresize utility to convert the document to standard letter size before sending it to the printer.

/usr/local/bin/psresize [-q] [-wwidth] [-hheight] [-ppaper] [-Wwidth] [-Hheight] [-Ppaper] [infile [outfile]]

psresize -PA4 -pletter in.ps out.ps (convert A4 to US letter)

As with all Unix commands there is a manpage with more usage details.