I need to make sure my understanding is correct.

 

Within a mod, I appreciate that 'things' (whatever that thing might be) are registered in order of Block, Item, <rest of the stuff in whatever order it happen>.

 

However, between mods, if one mod B is dependent on mod A, and is specified as such in mods.toml via ordering="AFTER", can I be confident that blocks from mod A will be registered before mod B registration begins?  That is, can mod B fetch mod A blocks and be confident they are registered?

 

I feel that's the whole point of indicating an order, but I've been caught by my own misinterpretations before.

Yes, since the event is synchronous, it should dispatch the event to the mods in the order they were loaded. If a mod has to be loaded after another, then the registry objects should be present when they are loaded into the registries. Just make sure your objects are deferred correctly else there will be errors when trying to construct the data.