If you have written an academic paper and wish to publish it in a journal, you are often asked to sign away your rights to that journal so that it may not be distributed in any other form. The SPARC Authors Addendum (the Scholarly Publishing and Academic Resources Coalition) is one way to distribute your article in ePrints or other repositories that are based at your university or within your broader field. It is a legal device, placed as an addendum to the usual Rights form submitted with your article. Details (US Organisation) may be found here (link). Thanks to Nick T for the link.
