The edding 8404 aerospace marker was specially developed for the aerospace industry to provide safe marking of components. Water-based ink is low-corrosion and resistant o many solvents and paints, and was approved by British Aerospace (BAE Systems) to ABP 9-3323 Class A (this presumably means something to someone!). However it also makes a fantastic garden marker - it writes on virtually any surface and is highly resistant to light and water.
