In a message written on Fri, Nov 12, 2004 at 10:35:38AM -0800, James Laszko wrote:
You've basically got to have around 16 /24's utilized before ARIN will
do anything for you. Once you're at this point, they'll give you a /20
to renumber everyone, but will reserve a contiguous /19 for you if you
can justify that you'll use it within the next 3-6 months.
Note, if you are multi-homed the prefix length is a /22.
http://www.arin.net/policy/2002_3.html