Template call site — a real caller in shipped template source; rendered with \snippet from the marker tag in that file.
Archived call site — the caller exists only in the source-of-truth tree compiled into libbento_secure.a; described as text (that source is not shipped).
Authored — no caller anywhere; the example is written for the docs and carries the authored banner.
WEAK hook — listed in template/lib/ble_nus/overridable.txt; the consumer implements it, never calls it.