An apparatus and method in which documents and enclosures are fed by feeding stations to a supply track and subsequently transported along the supply track to a gathering station. A sensor downstream of the feeding stations is used for scanning markings. A divert station connected to the supply track allows clearing the supply track, when scanned markings indicate that the first sheet of a next set has been scanned in the supply track, by diverting the first sheet to the divert station. This allows enclosures of the set being gathered to be fed along the supply track and gathered at the gathering station. After the completed set has vacated the gathering station, the diverted sheet is transported to the gathering station and gathered with further documents of the next set.