Memory failure

[Bugsy]

From another thread...
SGH - Sparse Gray Hackle, a fly pattern
modified to
SGM - Sparse Gray Matter, a different sort of pattern...

Ed

I'm not familiar with a fly pattern known as Sparse Gray Hackle, but maybe there is.

Sparse Grey Hackle was the pen name for Alfred W Miller, the noted angling essayist and writer for the WSJ, NYT and SI.