deetrMost users have a date in their prec file format and some sort of delimiter between the elements of the file format, it would probably be possible to regex it and get a pretty high accuracy. That would only work in most cases though and you want something that works in all cases from what I can see. Also you could probably not delete demos that start with esea_ imo because those will basically never be prec demos
I've added a simple checkbox and console command to allow users to only delete files containing the PREC's date var. Should be more useful now. If you rename files, you could get into the habit of saving these to a subdirectory.
Here's the new release: https://github.com/joelamos/prec_delete_useless_demo/releases/tag/v1.1