Almost always comes down to use in these instances. If you try and sell one of their/their competitors products/services via the site – you'd be asking for trouble. Parking it could be risky, but again it would depend on how that parking page is optimised and what ads are being displayed.
If you develop a site about county cricket/credit cards, etc, you'd likely have no problems.
Worth mentioning that abbreviation followed by date domains rarely sell for good money, and their shelf-life is very limited. I wouldn't bother with them myself.
- Rob