There is currently no dedicated constraint for making two faces or axes parallel to each other.
I am referring to a constraint that behaves similarly to an angular constraint set to 0° or 180°, but without defining a fixed distance between the selected entities.
Such functionality could either be introduced as a new Parallel Constraint or integrated into the Mate Constraint command as an additional option (for example, a "sliding distance" mode).
This would simplify many assembly workflows where orientation needs to be controlled while allowing unrestricted movement along the constrained direction.
