Harlequin Presents Extra
In April 2008, Harlequin began publishing four titles each month designated as Harlequin Presents Extra. This is in addition to the eight regular Harlequin Presents titles published each month. Each month's four releases are built two common themes. Prior to January 2010 each month's four releases were built around one common theme. For instance, the first month's theme was "In Bed With The Boss." The Harlequin Presents Extra books are usually all previously published in the U.K. by Mills & Boon under the Modern Extra imprint, Modern Heat imprint, Riva imprint or occaisionally Mills & Boon Medical Romance, usually with different titles.