You can allocate an Elastic IP address from an address pool owned by AWS
or from an address pool created from a public IPv4 address range that
you have brought to AWS for use with your AWS resources using bring your
own IP addresses (BYOIP). For more information, see Bring Your Own IP Addresses (BYOIP)
in the Amazon Elastic Compute Cloud User Guide.
[EC2-VPC] If you release an Elastic IP address, you might be able to
recover it. You cannot recover an Elastic IP address that you released
after it is allocated to another AWS account. You cannot recover an
Elastic IP address for EC2-Classic. To attempt to recover an Elastic IP
address that you released, specify it in this operation.
An Elastic IP address is for use either in the EC2-Classic platform or
in a VPC. By default, you can allocate 5 Elastic IP addresses for
EC2-Classic per region and 5 Elastic IP addresses for EC2-VPC per
region.
For more information, see Elastic IP Addresses
in the Amazon Elastic Compute Cloud User Guide.