-Z is used, dvips uses
texc.pro instead of
tex.pro. From the manual page:
-Z Causes bitmapped fonts to be compressed before they are downloaded,
thereby reducing the size of the PostScript font-downloading information.
Especially useful at high resolutions or when very large fonts are used.
Will slow down printing somewhat, especially on early 68000-based Post-
texc.pro most likely comes from compressed.
Since usually vector fonts should be preferred over bitmapped fonts (avoiding blurred displays of the PDF file in AR), IMHO the relevance of the option is a little smaller nowadays.