Here is where one reference for where it is talked about on the feather craft website.

"F-C "CRACKLEBACK" Pattern-Sheet by Ed Story. So many requests for tying instructions for Ed's F-C Crackleback Dry Woolly from customers worldwide. Updated pattern-sheet reflecting updated body-material and technique. A favorite trout fly pattern nationwide. It can be fished dry, or as a subsurface skipping emerger, all on the same cast(drift)! We've fished this one pattern from upstate CA, to upstate NY for a lifetime of success. Step by step tying and fishing instructions. $1.50 "

Don't know what a subsurface skipping emerger would do.