Verdy_p (2020-07-22 07:23:41+00:00): @trial: I meant this in the street name.
You speak about municipality and the hyphenation of municipality is no longer a requirement for "communes nouvelles" (it remains for communes déléguées).
As I said, in **printed postal addresses** you may (and even should) replace all hyphens and aopstrophes by spaces. This  transform does not apply here in OSM as we are not printing addresses on enveloppes and don't abbreviate them like on envelopes.
I've not said that hyphenation is systematic in "Le-Mans" still written "Le Mans" with a space in OSM and on printed addresses where it is also capitalized  after the postal code ("LE MANS"), or in "L-Isle-Adam", still written formally "L'Isle-Adam" in OSM, but written "L ISLE ADAM" in printed postal addresses (capitalized and replacing the apostrophe with a pspace only after the postal code).
For other parts of the printed postal addres (street names), the capitalization is not required (just suggested), but the replacement of all punctuation signs (including ".", apostrophe, hyphen) by spaces is preferable (as well abbreviations may be necessary to fit the length limit of these addresses or if there's the need to add precisions (building/room/door/level numbers, that don't fit on the limit of 5 lines);: for this, La Poste indicates abbreviations that should be used. If names are still too long they may be abbreviated further at end (e.g. "Route de la Chapelle-des-Fougeretz" may be printed on enveloppes as "RTE DE LA CHAPELLE DES FTZ" without any dot or hyphen.

Printed postal addresses are special, and FANTOIR contains some additional fields capitalized that exhibit the suggested non-ambiguous and capitalized abbreviations of street names (also without accents or cedilla). We don't want these altered names in OSM (except possibly in "short_name", but this is not needed if all what is abbreviated is the generic, like "RTE" instead of "Route" or "BD" instead of "Boulevard", as these abbreviations are predefined in a wellknown dataset, fully documented.
Other common abbreviations for postal addresses (outside street names or city names) include "BAT" for "Bâtiment", "ESC" for "Escalier", "PTE" for "Porte", "ETG" for "étage", "RDC" for "Rez-de-Chaussée". They are useful to fit more info on limited lines of addresses.

But the last line with the postal code must remain below the limit so the municimality name may be abbreviated in addition to being capitzlized and written without accents/punctuations

(it may be followed by an additional line for the country name when posting from another country, capitalized "FRANCE", as the convention of prefixing the French postal code by "FR-" is not universal in other countries, even if it could avoid an additional line; for example in it not understood when posting from outside Europe, notably countries where the Latin script is not well understood: using "FRANCE" in capital only makes this clear for the local postal services)
As well when writing from France to these countries, we should write their countries in plain text  (we an name therse countries in French, this is meant for the French postal service; the rest of the address above can be written using the script used at the target address, in Cyrillic, Chinese, Japanese kanas, Hebrew, Arabic... as this part will be read locally: the part above the country name uses the local conventions of the target country, including for the placement of city names street names and house numbers, postal codes, people name, and so on). Placing the country name at end on a separate line is sufficient (you can name this country in French, or in English, or abbreviated if it's well known like "USA").