Re-wiring an old Slater 3 way switch with new Leviton
Common is the black screw. Travelers are the brass screws.
And position does not matter at all on a 3-way switch.  You can buy 6 different brands of 3-way switch out of the bins at Home Depot and find 6 different positionings of those screws.
3-way switches have 3 screws + ground
A switch with 4 screws + ground is the wrong switch.
If it is a &quot;4-way switch&quot; (2 brass 2 black), by good fortune, you can wire it exactly the same way - 2 travelers on brass and third wire on one of the black screws.  Normally these things matter, but it happens to work out with 4-ways that it doesn't matter which black screw.  However, only use a 4-way for a 3-way if you enjoy paying $10 for a switch instead of $2.
If it's a &quot;smart switch&quot;, lighted, motion sensor etc., then it's more complicated.  You need to study your 3-way layout carefully and figure out where in the circuit it's possible for it to go.  At that point we'd need photos of the wires in the backs of the boxes, without anything disconnected (photos of a bunch of loose wires splayed out in every direction are worse than useless, and destroy the necessary information of &quot;how it was connected before&quot;).