sirwa69 while we do not refer to the co-pilot as "ballast" as yet, I'm sure it will find fertile ground if I introduce it to my colleagues!
We do however make sure to pester all young second officers with the following old joke:
What*s the difference between a 2nd officer and a duck?
A duck can fly.
A very well known skin care line, ph-neutral and soothing goes by the name Sanex in my home country.
What's the difference between Sanex and a CSD?
Sanex doesn't irritate.
Come on fishbed, SLF is a term of endearment.