May Day and QBI

[sveahk]

Hello,

Reading the book "Rendezvous with Fate" by Raymond Lallement, which is by the way definitely to be recommended, I came upon the following definitions:

May Day comes from the french "M'aidez".
The code "Q" and "Q.B.I." - letters invented by Belgian aviators before the war - stood for "Quel Brouillard Intense!".

The definition for May Day I've heard before but the QBI explanation is new to me.
Anybody like to comment...?

Greetings
Hans