http://roarmap.eprints.org/704/

"Funders should adopt a clear statement in favour of open access, provide a mechanism for funding gold open access and employ clear and binding mandates for green open access. They should encourage and work towards enabling gold open access publication and at the same time mandate green open access with an embargo period of no more than 6 months. Gold open access APCs should be based on an affordable, sustainable model and be monitored and recorded" [emphasis added]