When an organization qualifies for a block size that no longer remains in the ARIN IPv4 inventory, they are given the option to either accept a smaller block that is available to fully satisfy their request, or to be placed on the waiting list for unmet requests. As we do with all IPv4 tickets, we take action on customer responses in the date/time stamp order that they were received. We are able to look ahead in our IPv4 response queue and see that we will take the registration actions described above during this business week.
Once we take the registration action of issuing a smaller block than what was qualified for, or place an organization on the waiting list for unmet requests, we will issue an announcement to the community and a press release.
At the time of this post, there is less than 1% of a /8 equivalent remaining in the ARIN IPv4 free pool. The only prefix sizes remaining are /23s and /24s.
More information: https://www.arin.net/resources/request/waiting_list.html