clarify off-ness of WWNs

README.md

@@ -48,7 +48,7 @@ accidentally blink the wrong drive.  `megablink -u` also unblinks a drive.
 Notes
 -----
 
-* the Linux WWN is off-by-one from what megacli shows.
+* the Linux WWN is off-by-one or a few from what `megacli` shows.
 * thanks to http://serverfault.com/questions/381177/megacli-get-the-dev-sd-device-name-for-a-logical-drive/ for getting me to look in `/dev/disk/by-id`
 * thanks to http://www.network-administrator.co.uk/?p=575 for providing a handy reference to the megacli command structure
 * [lsidrivemap](https://github.com/louwrentius/lsidrivemap) is similar to megamap, but written in python and it has a nice table output format that shows the layout of the drives on the front of the server.