The phrase "all rights reserved" is now technically obsolete, though still in use. In this context, what does it mean to 'reserve' a right?
In particular, if one were to create a work, e.g. a piece of software, and provide a licence that conferred the ability to copy the software, would the copyright holder still have all their rights 'reserved', or does conferring the right to make copies mean that right is no longer 'reserved' by the author?
To "reserve one's rights" is to make it clear that some other action is not intended to give the rights up. Typically, it has no legal effect but is used out of caution, to avoid misunderstanding.
For example, an author who publishes their writing for free online might add "all rights reserved" to the copyright notice. This makes it clear that by making the work freely accessible, they did not intend to give others permission to republish it, or release it into the public domain.
Similarly, at an early stage of a legal dispute, a lawyer might write a letter of demand that outlines some of the client's strongest points, without wishing to imply that the case has been fully investigated and pleaded. Such a letter might "reserve our client's rights" to add to or amend the claim later.
In both cases, the legal situation would probably be the same if the rights were not expressly "reserved." They are, after all, rights. However, the phrase can potentially become significant when considering whether a party is estopped from asserting a claim that should have been raised earlier, or has made an unfavourable admission.
