Doors and Windows - door handing

I thought I understood this but am confused again.

I need to order some latch hardware, and the book says it fits LH or LHR. The other one fits RH or RHR.

Is it the case that LHR is sort of like a RH but the key is opposite? Or put another way, does LHR mean it is a door opening IN with the hinges on the LEFT as you face OUT?

The Adams-Rite book is confusing as to what I need to order, because it talks about some being field convertible, but not necesarily to all 4 configurations.

It has to do with the "action" of the handle.
Locks are configured in this way to insure that their installation is such that to unlatch, the action of the handle is down.

When the door swings away from you and keyed your side, the hinge side determines the handing. The same configuration pulling to you, is the handing reversed.

Open the door and stand with your back to the jamb with the hinges. Then, if the door is on your left, it is a left hand door. Conversely, if it is to your right, it is a right hand door.

txdiyguy,

That is fine for an in-swing door. But an outswing door is exactly the opposite!!

Well, I am starting to catch on! I got a spec sheet from Kaba/Ilco and this is how they define their locks: You stand on the outside (the side with the key) and if the hinge is on the left, it is left hand. If the door opens AWAY from you it is LH but if the door opens towards you it is LHR.

Thanks for the inputs.