The provided text indicates that a standalone as well as the local names are used. However, it is not immediately obvious from the provided example:
1. The external name is alized
2. The local name is low-case

I think it would have if perhaps the names in the example code would be somehow emphasized. Or a sentence is added that indicates that, for example the alized name of the external extention "USCoreRace" is mapped to the local name "race"

Existing Wording:

With standalone extensions, the main difference is that the grammar includes both the standalone name and the assigned local name: …