HylaFAX v<version><n>where <version> is found in the file VERSION and <n> is the number recorded in dist/hylfax.alpha. This string is also prominently displayed when you run the configure script to setup the software for compilation and each time the faxq scheduler process is started (look in the file where syslog messages are recorded).
If you have a binary distribution for a Silicon Graphics machine, <version> and <n> are displayed in "versions -n hylafax.sw"; for example:
I = Installed, R = Removed Name Version Description I hylafax 1006004075 HylaFAX Facsimile Software, Version 3.0beta I hylafax.sw 1006004075 HylaFAX Software I hylafax.sw.client 1006004075 HylaFAX Client Software I hylafax.sw.server 1006004075 HylaFAX Server SoftwareHere <version> = 3.0beta and <n> = 075 (the right three digits in the Version column), so this is HylaFAX v3.0beta075.
If you have a binary distribution for a SVR4.x you can use the pkginfo(1M) command to get the version number and the PSTAMP.