Qu'est-ce qu'un papier à en-tête d'entreprise

Ahh, fellow dev, so you need to write a Business Letter now...

Business letterhead is the header at the top of a company letter.
Letterhead usually includes a business’s logo, name, address and
contact information such as phone or fax number, email address
and company website URL.

lol, just open the first result :D
Index out of bounds