Readability:
t1 = "File " + MyFile + " was deleted on " + STRING(TODAY) + " at " + STRING(TIME, "HH:MM").
t2 = SUBSTITUTE("File &1 was deleted on &2 at &3", MyFile, STRING(TODAY), STRING(TIME, "HH:MM")).
I definitely prefer SUBSTITUTE in these cases and if you need to translate texts it will...