[gilbetron]

You encounter that all the time in the networking world - formally the bits outside of the prefix length should be 0, but informally you'll often see set bits. Often it is a way to say "the subnet that includes this ip address". So 192.254.33.12/16 or something. Could just be a typo, too. Regardless, it doesn't really matter what is in the bits outside of the prefix length, because they get zeroed out when used.

[gnfargbl]

Yeah, but that makes sense -- it's a shorthand for "the IP address 192.254.33.12 which is in the /16 subnet".