I was told it's full open minus half turn. So the next guy, if he
turns it the wrong way. It will turn "some" so that he knows it's not
a corroded and frozen valve stem. Then he will (maybe) figure out to
turn it the other way.

Works on globe, gate, and angle valves. Ball valves don't have a half
turn of play to work with.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..

One more tip: when you turn the main back on, turn it on full
and then
close it about an 1/4 turn - assmuning it's a compression style
with a
rotary handle. This gives you room to "play" if the main freezes
up
due to corrosion in the future. If you open it all the way
against the
stop, you won't have any "wiggle room" if it gets stuck.

This tip holds true for all compression style shut-offs, but is
not
(typically) a concern for ball valves.