Making sense of quantum mechanics/observational properties

a definition of "observational": experimental; relying on observation or experiment

The definition above is what I found in a Google search and I hope it is a good starting point. My understanding is that "observation" plays a rather fundamental and controversial role in quantum mechanics, so I want to be clear about the terminology "observational properties".

If I think about the position or velocity of a nail, it is easy to think of ways to measure position or velocity. The position of a nail at a particular time can be observed. However, I am uncomfortable with the idea that the position "relies on observation or experiment". In my mind, a nail has position even if there is no observation or experiment done to measure the position.

In quantum mechanics, is there a distinction to be made between "observable property", "observed property" and "observational property"?

I'm not sure what distinction is being drawn by the term "observational properties". Are there also "non-observational properties"?