An acronym can acquire a different meaning in another service or period. The Swordfish's torpedo-spotter-reconnaissance role supplies the naval use of TSR. A later RAF tactical-strike usage does not invalidate that earlier designation. Comparing the service and date of each usage resolves an apparent contradiction without assuming that one expansion was universal.
Notable Point · 8:10:58-8:11:46
Why TSR means different things in naval and RAF usage
Swordfish terminology illustrates why an acronym must be read in its service and historical context.