Securing Oatey 42213 tile drain

I am having a hard time finding out how to secure the Oatey 42214 tile drain to the subfloor. There are no predrilled holes in the drain base. Does anyone know if your supposed to drill holes yourself, or does the weight of the mortar/tile hold it in place. These are the manufacturers installation instructions.
http://www.oatey.com/shower_drains/lit/Shower Pan Liner.pdf

Thanks.

It doesn't secure to the floor, it sets on the floor.
Since you clamp onto the vinyl liner, and that has mortar over it, it's not going anywhere.

For your tiled shower, you may want to also check out www.johnbridge.com. They have some info in their 'Liberry', and a very active forum specifically on tiling issues.

Thank you for your help.