Since a single note can appear into multiple places in the Note Tree via a process called Cloning Notes, it's recommended to choose a generalized name that fits into all locations instead of something more specific to avoid confusion.

In some cases this isn't possible so Trilium provides "branch prefixes", which is shown before the note name in the tree and as such provides a specific kind of context.

The prefix is location-specific, so it's displayed only in the note tree.