Modeling question in etabs, What Etabs does to a shell element to make it "ribbed" ?

[GJoeRMK]

Greeting,
What Etabs does to a slab shell element to make it "ribbed" ?

I found an article that claims that a ribbed shell elements mimics the orthotropic stiffness of the element if you select this type, but not idea what are the exact modifiers values

Ribbed and Waffle objects: These objects can be used to model ribbed and waffle slabs. The generated finite elements have an orthotropic stiffness corresponding to the geometric data defined in the cross-section properties. The weight and mass of these objects are calculated excluding any lost formwork, so in these cases, the user must define mass and weight modifiers to account for the action of these non-structural elements. The design and detailing of these slabs also consider the geometric data of the cross-section.

I should be able to make a simple slab shell element and modify so I get as the same response as I would get using a shell ribbed element