ubicoo/yourls-pseudonymize — comment on commit 914b0acb86349b6ad6ba718e4be2c8d708d8ecea
File:  line 0
By bmhm:

BTW: I don't think IPv4s at the end of IPv6 addresses need special treatment.
2001:470:1f0b:692:6e62:6dff:fe3e:faf => 2001:470:1f0b:692:6e62:6dff:fe3e:0
2001:470:1f0b:692:6e62:6dff:fe3e:127.0.0.1 => 2001:470:1f0b:692:6e62:6dff:fe3e:0

You might still have all the information you need (like geographic information, or, in my case, 2001 for a tunneling address).