I did not know!
"Not needing root to administer Linux - the home of libcap"
https://sites.google.com/site/fullycapable/
I discovered this while investigating the source for
"C library for Broadcom BCM 2835"
http://www.airspayce.com/mikem/bcm2835/
--
Brian Lavender
http://www.brie.com/brian/
"There are two ways of constructing a software design. One way is to
make it so simple that there are obviously no deficiencies. And the other
way is to make it so complicated that there are no obvious deficiencies."
Professor C. A. R. Hoare
The 1980 Turing award lecture