An Open Access publication is one that meets the following conditions:
The author(s) and copyright holder(s) grant to all users a free, irrevocable, worldwide, perpetual right of access and a license to copy, use, distribute, transmit and display the work publicly and to make and distribute derivative works in any digital medium for any responsible purpose, subject to proper attribution of authorship, as well as the right to make small number of printed copies for their personal use.
A complete version of the work and all supplemental materials, including a copy of the permission as stated above, in a suitable standard electronic format is deposited immediately upon initial publication in at least one online repository that is supported by an academic institution, scholarly society, government agency, or other well-established organization that seeks to enable Open Access, unrestricted distribution, interoperability, and long-term archiving (for the biomedical sciences, PubMed Central is such a repository).
Open Access is a property of individual works.
Community standards, rather than copyright law, will continue to provide the mechanism for enforcement of proper attribution and responsible use of the published work.