A symbol used in the natural gas industry for 1 billion cubic feet of gas equivalent (cfe). This is really an energy unit equal to about 1.091 petajoules (PJ)
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}