I try to be a good serials librarian and blog journal-related OA announcements, Recently, I've paid particular attention to announcements about hybrid journal programs but I missed this one. I'll mention it in brief here.
On August 3, BMJ Journals announced that they now have an option by which authors with papers accepted for publication by a BMJ journal can pay to make their papers open access. This program is called Unlocked. Unlocked employs a two-tier pricing system, charging either £1,200/$2,220 US/€1,775 or £1,700/$3,145 US/€2,515, depending on the journal.
Unlike some of the other recently announced hybrid programs (e.g. Elsevier, Wiley, Cambridge), it looks like the Unlocked option applies to all of the titles in the BMJ suite of journals; no list of participating titles was given in the announcement.
And yes, the BMJ annoucement does use the words "open" and "access".