On the evening of 19 June 1978, witnesses in Gujan-Mestras near Arcachon reported a bright aerial object moving above the town.

This case matters because it is a documented government event whose object identity remains unresolved.
Documented
On the evening of 19 June 1978, witnesses in Gujan-Mestras near Arcachon reported a bright aerial object moving above the town.
Debated
The identity of the object
Debated
The adequacy of the conventional explanation
Unverified
Extraterrestrial origin
Unverified
Any claim stronger than the record supports
Sources are kept in separate layers: official and contemporary material is documented; secondary UFO literature is treated as debated, not as primary evidence.
Secondary / debated material.
Documented source.