I see no reason to disallow %F:
$ jot -w '%F' 11 0 1
jot: illegal or unsupported format '%F'
while 'jot -w '%f' 11 0 1' works just fine. Granted, jot isn't going to
print inf or nan, so there is no visible difference between '%f' and
'%F', but the above command seems perfectly legitimate to me.
Note however that FreeBSD and NetBSD don't allow %F either.
Index: jot.c
===================================================================
RCS file: /var/cvs/src/usr.bin/jot/jot.c,v
retrieving revision 1.43
diff -u -p -r1.43 jot.c
--- jot.c 12 Jan 2018 06:22:31 -0000 1.43
+++ jot.c 13 Jan 2018 07:53:40 -0000
@@ -427,6 +427,7 @@ getformat(void)
case 'e':
case 'E':
case 'f':
+ case 'F':
case 'g':
case 'G':
if (longdata)
