yeah...thats nacco engineering for you
they give you diagrams showing the connections but left out the most important part... they forgot to label the connections.

But yes,
T would be return (actually runs to the brake booster valve)
P (comes from the pump)
R (to right steer cylinder connection)
L (to left steer cylinder connection)

its funny though, they say to make sure you connect the lines correctly but don't show any labels in the diagrams, and then follow that up with a caution note about hooking up the lines wrong will cause damage.
And if by some strange chance they did put it in the manual somewhere it might be in a section that has totally nothing to do with the steering or hydraulics, sometimes they hide tidbits of info like that in obscure places.
I looked all through both hydraulic and steering sections and nothing...nada... :o/
DOH!