N Cook wrote:

For permanent marking missing legends or other added comments to black cased
ICs.
Do they exist?, not necessarily Staedler or even white , just something
thats not dark red,green,black or blue, that stays on and contrasts with
black plastic.

They exist. I even have white artists pencils. Check art supply stores -
not office supply stores. IIRC you are looking for something used to
retouch blue prints.

Rick