[tz] Chile TZ rule 1942 June superfluous?

I do not understand the purpose of the line for June 1942 in the Chile rules: # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Chile 1927 1932 - Sep 1 0:00 1:00 S Rule Chile 1928 1932 - Apr 1 0:00 0 - --> Rule Chile 1942 only - Jun 1 4:00u 0 - Rule Chile 1942 only - Aug 1 5:00u 1:00 S Chile was on GMTOFF -5h from 1927 to 1947. What purpose has that line which does not change anything, as no DST was in force before that date: Rule Chile 1942 only - Jun 1 4:00u 0