Parked Domain Detection

Heyo.

I'm currently trying to find a way to check if a bunch of domains are parked or not. My method at the moment is a basic heuristic that checks for

• if title or body contains –> domain is parked | domain is for sale | this domain is for sale" and other flags like that
• if there are any links with the text "buy this domain | purchase this domain" etc.
• A few other text heuristics like that

But it feels like a very crude way of doing this. I thought about creating a DNS record registry of domain parking service providers but even that will never be reasonably large enough.

Any ideas, tips, or tricks anyone can share that could help me tighten this up?

Thanks