A "Raff Degression Channel", named after Gilbert Raff I guess, is one of many types of trend channel, but I believe "Raff Degression Channel" is too specific for your context here. The term "trend channel" is probably close enough. "Trend channel" draws over 6000 pertinent Google hits, such as:

http://www.straitsindex.com/etutorial/Trendchannel.htm

"Trend channels also classified in two types : Ascending trend channel and Descending trend channel. Trend channel is a parallel line that trace against the trend line, connecting the significant tops in an up trend and the significant troughs in a down trend."

http://www.2kcity.com/stocks/charttips/horizoltrend.asp

"If connecting the price tops of a particular stock or index compose a horizontal line parallel to a line connecting the bottoms of that stock or index, the Horizontal Trend Channel is the area between the two lines."

http://www.iqchart.com/cobrand/hedgehog/education/chartpatte...

"If connecting the price bottoms of a particular stock or index compose a downward sloping line parallel to a line connecting the tops of that stock or index, the Descending Trend Channel is the area between the two lines."

http://www.updata.co.uk/onlinemanuals/analytics/trendchannel...

"The Channel function will draw a set of parallel lines automatically through any selected period on the graph. The lines for the Channel are drawn 1.96 standard deviation from the central regression line, resulting in 95% of the data within the specified period falling inside the channel. To draw a trend Channel on a graph -or- Click on the Add Channel Trends icon"

http://www.traders.com/Documentation/RESource_docs/VolAbs/V1...

"Enhancing The Raff Regression Channel A market follows its primary trend in a zigzag form. The trend direction is easy to see; the real challenge lies in identifying the minor trends."

http://store.traders.com/traderscom/-v12-c05-raff-pdf.html

"Stocks & Commodities readers have suggested that we interview someone who did not start his or her career in the financial community but was successful enough in the markets to change careers midstream to trading. Gilbert Raff is one such individual. Raff, who was a cardiologist with a background in physics who has also written for Stocks & Commodities, left his medical career to manage money. S&C Editor Thom Hartle spoke with Gilbert Raff about why he changed careers, the similarities between assisting people in managing their health and their money and the methods he uses to identify market opportunities."

HTH - Dan