Symbolic modes use mode 0 as a point of departure

[Dan Jacobson]

 - Test: -perm mode
     True if the file's permissions are exactly MODE (which can be
     numeric or symbolic).  Symbolic modes use mode 0 as a point of
     departure.
Sounds like we are about to take a vacation and are at the boarding
gate... therefore add examples. Indeed, examples need to be added for
the whole paragraph. (Various musings:)
find . -perm 666
find . -perm 0666
find . -perm +22
find . -perm -22
find . -perm -0
find . -perm +0022
find . -perm +w
find . -perm +0w
ls -Rl|grep rw-rw