Can someone explain this difference between a reserved and an unreserved train?

Friday I had a ticket on a reserved train, but had to search long and hard to find a seat. Yesterday I had a ticket on an unreserved train, and found my seat the same way.

So obviously the seats aren't reserved, just the # sold, right? Does this mean that you could be denied boarding on an unreserved that is too full? Is there anyone out there that this has actually happened to?




[This message has been edited by srodr (edited 09-15-2003).]