This commit 244106 implemented -T and -W options but -R was added to the manual page (.Sh SYNOPSIS).
% sysctl -Ra sysctl: illegal option -- R usage: sysctl [-bdehiNnoqTtWx] [ -B <bufsize> ] [-f filename] name[=value] ... sysctl [-bdehNnoqTtWx] [ -B <bufsize> ] -a
The official style is AaBbCc not ABCabc. This is true for both the usage() message in the program and the usage in the man page. longopts are a total crap shoot, we have no standard for those, but single letter ops are well known: alphabetical order, with the upper case of the letter immediately before the lower case.