Define unambiguous distance restraints

Hello, I would like to upload my own tbl-file with unambiguous distance restraints between two atoms. Could you let me know the format of such distance restraints ?
From previous topics I found this line, possibly defining a distance restraint between atom HN from chain A and atom O from chain B. But I am unsure what the numbers at the end mean:

ASSIGN (segid A and resid 97 and name HN) (segid B and resid 133 and name O) 2.0 0.2 0.3

I imagine there should be a force constant and a minimum and maximum distance ?

Many thanks
Andreas

ASSIGN (segid A and resid 97 and name HN) (segid B and resid 133 and name O) 2.0 0.2 0.3

I imagine there should be a force constant and a minimum and maximum distance

The force constant is not part of it. The three numbers at the end define the upper and lower limit distance:

Lower limit: first - second, i.e. in this case 2.0 - 0.2 = 1.8

Upper limit: first + third, i.e. in this case 2.0 + 0.3 = 2.3

All this is defined in a Box of our Nature Protocol server paper. But it is also standard CNS/XPlor syntax.