Open Access via PubMed Central

"[Until recently,] to be indexed [in PubMed/Medline] and obtain the additional traffic, journals had to deposit "all articles" in PMC, which is open access, and was the only "site acceptable to NLM". A recent development threatens to cut off this supply of open access articles, leaving only the small proportion whose funder requires deposit in an open access repository....ITHAKA has negotiated a deal with the NLM under which e-only articles deposited in Portico [a dark archive] will be indexed in MEDLINE without being deposited in PMC....Previous to this deal, to be indexed in PubMed articles had to be deposited in PMC, and thus made publicly available, even though doing so was not required by the law (or by the funder).After the deal articles whose deposit is not required may be deposited in Portico, not deposited in PMC, and thus no longer be publicly available although still indexed in MEDLINE. This agreement does not violate the Public Access Law, but it decreases public access to research. As more publishers move to e-only the implications of this agreement will continue to grow. In particular, NLM has given up the leverage (indexing in MEDLINE) it used to have in negotiations with the publishers."