Nested footprint

[kcs]

I would like to know what are the best practices to make nested footprints. Could anyone provide a sample library where there is one component that has a footprint designed to accept three or more different cases. I am particularly interested to know how and where do you define which pads of each sub-footprint are connected.

[ajb]

You mean a single footprint that will accept, say, an SO8 or a DIP 8?  You can link multiple pads to a single schematic pin by giving them all the same designator in the PcbLib.  This works best if the different packages all have mostly the same pin mappings.  Otherwise, you could just place all of the footprints you want on the PCB/schematic as separate components, which would give you maximum flexibility--and you should be able to use design variants to indicate which package is actually fitted in any given situation.  You'll need to create a suitable design rule to avoid clearance violations if the footprints intersect.