The root collection shown in the Outliner is displayed as Scene Collection, but it is called differently in other places:
Master Collection (
- Master Collection for Scene (in code and code comments)
- Scene Master Collection (in code and code comments)
This is pretty inconsistent. It might have historical reasons, but AFAIK all of them refer to the same thing and it should be called the same everywhere to avoid confusion.
Master Collection sounds too much like a single global collection, which it is not (it is per scene). Scene Master Collection describes it best but if the name Scene Collection in the UI is final then that should be at least used as collection name (Python example above). In code comments Scene Master Collection could be kept as it is easier to understand, but grepping for scene collection will not find it.