[ALUG] When did this start?

Just been re-zapping a RaspberryPi and noticed that / has: lrwxrwxrwx 1 root root 7 Mar 4 22:45 bin -> usr/bin/ lrwxrwxrwx 1 root root 7 Mar 4 22:45 lib -> usr/lib/ lrwxrwxrwx 1 root root 8 Mar 4 22:45 sbin -> usr/sbin/ When did bin lib and sbin become links, and what's the rationale? Is this from Debian? -- Red to red, black to black, switch it on, but stand well back.