Quote JCandeias (

)
Say I'd like to put a ship in orbit around, say, Io
Hopefully we can actually do this in SE soon
Quote JCandeias (

)
In its ParentBody tag I'd only put "Io", right? But which Io? The moon or the asteroid? Unless I'm mistaken, the code has no way of distinguishing between the two.
Good point, I hadn't thought of that... however, since each of those objects has an alternate name, you could simply use that.
Quote JCandeias (

)
But it might be a problem when names are randomly generated.
It's best to try to make sure that each name is unique, or that each object has more than one name. But yes, being able to use the hierarchy like in Celestia to distinguish objects would be a nice feature to have to make these sorts of things easier.
Quote JCandeias (

)
Oh. I thought that thread was only for frequently asked questions, not for the occasional unusual question.
Even a frequently asked question must be asked a first time
SpaceEngineer's intent was that all questions be asked there, and the most commonly asked ones would be added to the OP, thus forming an FAQ.