When it was made available in France in early 1984, this PAL Atari 800XL came to fill a gap that had to be occupied by Atari. The Atari 800 was a machine from the past. The Atari 1200XL (NTSC only) had not been imported in Europe. The SECAM Atari 800XL was not ready yet, but the competitors were already there and occupying the market. I'm mainly referring to the Commodore 64 and the Apple II in the case of the French market. So, Atari France had no choice but to make available a PAL machine in a SECAM country. The machine was priced approx. 3.500 French Francs. But for an additional 900 Francs, you could easily buy a PAL to RGB converter: that colour signal physically transported by a PERITEL/SCART connector could be plugged and decoded by any SECAM TV set available in France (PERITEL connectors were legally mandatory on TV sets at this time).
Some movies enthusiasts, already owning high end equipment such as PAL LaserDisc players, etc, already had a PAL & SECAM TV set, able to decode both signals. These amateurs were able to plug their PAL Atari 800XL directly in their PAL & SECAM TV set.
The PAL to RGB converters manufactured by "CGV" (the company still exists, www.cgv.fr) were very popular and widely available in the computer shops, especially the PVP80 model (actual pictures available: cgv-pvp80.zip).
Atari also sold the PVP80 rebranded as an Atari device.
Remark #1: The serial number sticker was removed by a 13yo technician, during a space bar repair operation, because he believed the sticker was hiding a screw. Eventually, he was proved wrong but the serial number sticker was destroyed in the operation. I still regret it today.
Remark #2: The French sticker reads "Si cet appareil est directement connecté sur la prise d'antenne de votre téléviseur, il est interdit d'utiliser un dispositif de raccordement permanent non homologué. En cas d'infraction, l'usager s'expose à des poursuites.", which could be roughly translated as "If this device is directly connected to the antenna plug of your television set, it is forbidden to use a non homologated cable for a permanent use. If case of malpractice, the user can be sued."
PAL vs. SECAM versions
Using 'PEEK' commands in BASIC to find out about the OS, Basic and GTIA versions.
For your information, the results are:
PEEK(53268) = 1 [PAL/SECAM]
PEEK(65528) = 140 [Not a 400/800]
PEEK(65527) = 2 [XL OS Rev. 2, 1983-05-10, 800XL(most)/65XE(most)/130XE(most)]
PEEK(43234) = 96 [Atari BASIC Rev. B]