Could somebody please clarify the meaning of these two expressions and the differences between them: "All Right Reserved" and "All Left Reserved"?
I think your question is related to Copyright and Copyleft.
The Copyright is when the material copyrighted can't be acquired with non legit media (downloading, piracy) and can't be copied, distributed in any way, unless there is an explicit permission by the owner or the company that owns those rights.
"All rights reserved" means that nobody else has those rights, except for the author/owner of those rights.
The Copyleft is a play on that and is basically the opposite, meaning that whatever has the copyleft applied can be copied, downloaded, distributed and maybe even modified, although that can be under Conditions (expressed by the author).
But in this case the expression became "All rights REVERSED" and not "reserved" to indicate the change of meaning.
If you look on Wikipedia there's more info, I just gave you the most basic ones.