French citizens often have several first names, which are mentioned on their passport. Are French citizens supposed to indicate all their first names when booking a flight ticket?
On one side I read that airline ticket names must match ID exactly (mirror). On the other side, some mainstream airline websites (e.g., American Airlines) have a maximum field length for the first name(s), which don't allow entering over ~13 characters, which typically isn't enough for several first names.
The linked article is over 10 years old, and contains the interpretation of a journalist. In practice, using your usual first name and last name is the usual way, and works perfectly fine.
The main point of that regulation is to not abbreviate your first or last name, change the spelling, or use nick names.
Especially in the US it is very common to use a nick name that is (or is not) derived from your given name, like 'Dick' for 'Richard', or 'Joe' for 'Joseph', or 'Bob' for 'Robert', etc. People were used to using these short forms when booking flights before that change.
Of course, if you ask around, you'll always find someone that isn't sure and recommends to use all you first names, or 'be on the sure side and call the airline'.that works, but costs you time and money, and is unnecessary extra effort.
It's usually best to type exactly what it says in your passport to avoid any issues or problems at immigration.
If your name doesn't fit in the name field it is probably best to call the airline and to book over the phone.
Or as suggested by phoog:
Another option would be to ask the website user support how to handle the specific name. Something like "My given names are Elizabeth Christina Genevieve Isabella Gwendolyn Esmeralda; how should I enter my name on your website?"
