IANA gives criteria on this topic. For IPv4, here is what they may have in their "Specific goal tackle registry". That means, for our purposes, nearly anything in these deal with blocks should not be assigned given that they shouldn't be routable "publicly". Stack Exchange network contains 183 Q&A communities https://frozen-activity-table-set40726.blogs-service.com/67595841/what-does-255-payday-loan-mean