Limit screws on early 90's Shimano Altus derailleurs
 

I'm tinkering around with an early 90's Cannondale M300 mountain bike. The rear derailleur is a Shimano Altus C10 and the front derailleur is a Shimano Altus A10. The limit screws on both derailleurs are not marked with H or L. Can someone tell which screw is which on both derailleurs? Is there an easy way to identify them if not marked or perhaps a rule of thumb? Thanks in advance for any feedback.

https://cimg8.ibsrv.net/gimg/bikefor...46fd63fa1b.jpg


https://cimg9.ibsrv.net/gimg/bikefor...c49cda895f.jpg

You just have to look at how the derailleurs' body move in relation to those limit screws and after that it becomes clear which one is which. Looking at the derailleur from the underside normally helps to determine that. Anyway, my guess is that for the front one, the closest to the seat tube screw would be L and the other one would be H. For the rear one, the lowest one would be H and the other one L.

I'm still a bit confused. The body is going to move in and out regardless of which screw is being adjusted clockwise or counterclockwise, correct?

Nope, not really.
Here is how to determine which screw is which.
Front derailleur. Shift to the lowest chainring. The screw which while being tightened (clockwise) moves the body outwards is the low limit screw - L. The other screw is the high limit screw - H. If you shift to the big chainring and start tightening the H screw the body should star moving inwards.

Same goes for the rear mech. For L screw, switch to the bigggest cog. For H screw, you need to switch to the smallest cog.

Check this article if it's still unclear.