Debian policy mentions a "version number" in a number of places. I think it is misleading to call it a number, a version string would be more precise.
Calling it a version number may give people the false impression that a '.' is a decimal point rather than a seperator. Also its a stretch to call it a number given the variety of non-digit characters allowed... and that when these non-digit characters are used they arent consistently used in a mathematical sense. In chapter 4 it states "The version number format is: [epoch:]upstream_version[-debian_revision]" ===============^ And later... "The upstream_version may contain only alphanumerics[14] and the characters . + - :" Glenn
