Jim,
I thank you for your great amount of feedback. I will check your objections and additional arguments in favor of natural keys, and I will make an effort to make the next version of the document less biased.
Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)