Instrument rating prerequisites

Hi all.

A quick question about getting the Instrument rating: you have to have
50 hours of cross-country pilot-in-command time, right? How is
cross-country time defined for this purpose? I couldn't find anything
in the FAR AIM that defines it. I guess maybe it is the same as the
definition for the Private, which I believe is flying to an airport at
least 50nm from the start point.

Does anyone know for sure? Also do you have to land at another airport
for it to be cross-country or do you just have to go there?

If anyone has the precise definition I'd appreciate it.

Thanks

Tom