Should I address a "Charge de Recherche" or "Directeur de recherche" in France as "Prof."? In France, the following are two of the main ways people get promoted in academic positions:

Maître de Conférences (assistant professor whose responsibilities include teaching as well as research) -&gt; professeur (professor)

and

Chargé de recherche (in charge of research) -&gt; Directeur de recherche (director of research).

Note that in the second sequence of academic promotions, one doesn't have to teach and the positions are mostly dedicated to research (although one can opt to teach if s/he wants to).
My question is: while applying to a position (postdoc/permanent) in the team of a chargé de recherche where s/he is the PI of the project, should one address her/him as a professor (&quot;Prof.&quot;), say in the cover letter? It's technically incorrect it seems, but perhaps no harm is done because their positions are equivalent to those of professors anyway.
I'd like to know the viewpoint(s) of someone(s) who's familiar with the French system!
French academia is not big on titles. Whether it's by students, colleagues, or the administration, people are rarely if ever addressed by their titles. I'm a &quot;maître de conférences&quot; myself, and nobody addresses me as anything other than &quot;Monsieur&quot;, and my colleagues of another gender are addressed as &quot;Madame&quot;. That's it, no fluff, no &quot;Prof Dr&quot;, no &quot;Maître&quot; -- which wouldn't be appropriate as this is how you address attorneys and notaries, not even &quot;Dr&quot;.
If you want to err on the side of the formality, which is perhaps better until you know more about the person in question and how they like to be addressed, you can call them &quot;Prof&quot;. It's inaccurate, yes, but we are used to the outside world wanting to impose American title norms on us. You can take comfort in the fact that many institutions have &quot;research professors&quot;, so a chargé de recherches could be viewed as a &quot;junior/associate research professor&quot;, that you would address as &quot;Prof&quot;, indeed.
Personally I wouldn't care if a foreign applicant started an email with &quot;Dear Mr. XYZ&quot; (or Ms. as appropriate), and I doubt (m)any of my colleagues would. But I hesitate to give this advice, as it's possible that in some French academic subcultures some people give more importance to titles. I'm thinking of law and medicine, especially.
However, do not ever address someone as &quot;Dear Chargé de recherches Dupont&quot; or &quot;Dear CR Dupont&quot;. That's just not used as a salutation, even if it's the title used by that person on their website.