I think that I can best describe my question by giving two examples:
This is a TRS audio jack: https://uk.farnell.com/lumberg/1503-03/connector-receptacle-3-5mm-phono/dp/1216980. It has two plastic "bumps" (I don't know how those things are really called) and the datasheet clearly shows their location and dimensions.
This is a card edge connector: https://nz.rs-online.com/web/p/edge-connectors/6812238. It has four plastic "bumps" at the corners and the datasheet doesn't mention almost anything about them.
So I assume that in the first case, the plastic things are for mechanical stability, they need to fit inside the pcb, and when I'm creating the footprint for the component I need to add (possibly NPTH?) pads for them.
And in the second case, I assume that the plastic things are for something else (spacing? I don't know?) and I don't need to include them in the footprint.
Is my line of reasoning correct?