When are capital letters required in product names?
Product and brand names are expected to follow the standard rules for proper names, i.e. start with a capital letter, but they are never required to do so. They are "free" proper nouns and are not required to comply with any orthographic or grammatical rule, especially when used in advertisements and logos. In France, they are registered (déposés) at the INPI and the property of their owners.
For example, the obsolete brand name :
used to break the uppercase requirement for France and the accents requirement in télécom.
It is now called Orange but its logo still uses a full lowercase spelling:
The same can occasionally happen for product names like this one :
or that one:
There are also opposite cases where the whole product is written in capitals, but doing it doesn't break the French orthography rules. Only the first letter is considered a majuscule, the other ones are just capitales. e.g.:
The same name might also be registered with the opposite capitalization:
In plain text, the proper noun requirement for an initial uppercase is normally prevailing so a sentence using that brand name will read Orange, une Twingo. On the other hand, if a product name becomes so widely used that it becomes a common name, its leading uppercase letter is often lost. e.g. un bic, un vélux, un caddie, une freebox, ...
Of course, product names like iPhone keep their non standard spelling, nobody writes Iphone, but un ThinkPad is often written un thinkpad and sometimes un Thinkpad.