What is the difference between the ocf:heartbeat:IPaddr and ocf:heartbeat:IPaddr2 types?

Issue

If I compare the descriptions for both resource types there are no differences besides the names:

# pcs resource describe IPaddr2 > /tmp/IPaddr2.txt
# pcs resource describe IPaddr > /tmp/IPaddr.txt
# diff -s /tmp/IPaddr2.txt /tmp/IPaddr.txt

< ocf:heartbeat:IPaddr2 - Manages virtual IPv4 and IPv6 addresses (Linux specific
<                         version)
---
> ocf:heartbeat:IPaddr - Manages virtual IPv4 and IPv6 addresses (Linux specific
>                        version)