Its not a breeder or seedbank, clone only strains are only available as clones. Mostly they are special selected phenotypes of a commercial strain, or old classics who was keeped by someone somewhere...

Info from Dynasty Seeds:

The cough is a very special clone only cut of an Old NL#5/Haze.. I first received The Cough in the late 90s from a friend who moved to Oregon from Colorado... At the time I was gifted the cut, I was told it was the original NL#5 clone crossed with a Haze Bros Haze that he had been growing in colorado... He assured me this strain is NOT the same as the NL#5/Haze that came from Amsterdam... It is named 'The Cough' for a good reason, it Makes you COUGH... She has nice medicinal values, great yields and is Powder Mildew resistant... I've seen her in rooms covered with PM and she never once showed any signs of it..

With her 12+week bloom time, she is an advanced strain to grow which made her close to extinct when everyone went for faster blooming strain as the Kush trend took hold of the scene.... I knew how special she was, and could not bring myself to let her go... Over 13years later I still have the original cough that I was gifted..