Today at work I came across an old web form that a client still uses with this warning about Netscape browsers.

If you use Netscape 6.0 or above as your Browser please note before proceeding: Netscape (6.0 and above) has a bug which may cause a security flaw when submitting your listing. To avoid possible errors, we recommend that you access an older version of Netscape (5.0 or below) or a different Browser.

For context, Netscape 6 was released in November of 2000. This form has been around 21 years!