those marks are the same kinda thing as the little papers ya find in the pocket of yer new shirt - "quality inspected by #71".
lets someone further down the line know who passed the f-ups along. just meaningless consumer- goods-factory doodles.

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature we find it attached to the rest of the world" John Muir
"When we tug a single thing on an old truck, we find it falls off" me
Some TF series details & TF heater pics & Rust-a-holics Unanimous parking lot