IANA IPv4 Address Space Registry

Recently I found a problem with some website, which I could not see from one specific network. After long investigation, including owner of that website, we found that website was very particular about filtering all but only valid IP addresses. The problem was their table of valid address space was not valid. The current one should be at http://www.iana.net/assignments/ipv4-address-space/ipv4-address-space.xml Interesting is list of 12 unallocated prefixes, (e.g. 005/8 = 5.0.0.0):  5,23,37,39,100,102,103,104,105,106,179,185.
It’s more then 4% of address space.