This is a series of unknown duration, and it's based on the premise that not all offseasons are created equal. (sbnation.com)
I saw pretty much every stock on my watch list with a big «manager's special» sticker slapped on it, begging me to take advantage of the limited time offer of unknown duration. (dividendswithchildren.com)
The company had licensed this technology from e-Ink Holdings in an exclusive licensing agreement that prevented the competition from adopting it for an unknown duration of time. (goodereader.com)