Update operation cannot update an existing name or address. If you don't wish to update an existing name or address, you should keep those fields empty. All names and addresses contain in the representation will be added to the Person resource, as new names and addresses.
When the server processes this update, it performs a search using its standard search facilities for the resource type, with the goal of resolving a single logical id for this request. The action it takes depends on how many matches are found: