[imtringued]

Well, the problem is that FreeCAD is in the wrong here, but you are also making mistakes as well.

* The correct term for "slider joint" is "prismatic joint".

* "ball joint" should be "spherical joint" (nit picking, but still)

* "Revolute joint" and "cylindrical joint" are correct

Now comes the list of things which aren't joints and should be called constraints instead:

* Distance Joint

* Parallel Joint

* Perpendicular Joint

* Angle Joint

* Rack and Pinion Joint

* Screw Joint

* Gear Joint

* Belt Joint

Now to your mistakes. There is absolutely nothing wrong with calling revolute, prismatic and spherical joints joints. They are joints, they do what joints do, hence the name joint. The physical interface is your responsibility as the designer.