Would someone mind explaining the difference between "Commercial" and "Personal" as it relates to taking and selling prints...

I was looking through old negatives, and found an older image I want to make a few prints to sell....in this case an adobe cultural center...but...

When I shot the image, I was in the parking lot of the property, and after setting up, taking the shot, and had loaded everything up....a person came out and asked that I come inside and sign a document...I believe it was a release stating the image was not for commercial use - (if I recall correctly, it was about 14 years ago)...

It got me thinking that I have signed a few similar releases over the years...."not for commercial use"....Indian pueblos and the like....

Can I not sell these images as fine art prints? or is simply selling a print considered commercial in these cases?

I searched, with no results - but if this question has been asked before - please point me to the posts, or thread...

Thanks,
Dan