Yes Colin, you're right. PWR is not in the FreeBSD list of signals, per # kill -l HUP INT QUIT ILL TRAP ABRT EMT FPE KILL BUS SEGV SYS PIPE ALRM TERM URG STOP TSTP CONT CHLD TTIN TTOU IO XCPU XFSZ VTALRM PROF WINCH INFO USR1 USR2 LWP
Also doesn't appear in Open Group Base Specifications Issue 7 list of signals https://pubs.opengroup.org/onlinepubs/9699919799/ Cheerio.
