For future reference, I feel it is worth recording here that for pharmaceuticals, and in Europe at least, 'fanciful trademark' is not said. Instead they speak of 'invented name'.

Remarkably, the European Medicines Agency (EMA) does not speak about “Trademarks” but calls it “Invented Names”. It is a requirement of EMA that there is only a single Invented Name for a drug and this name should be used in all 27 Member States of the European Community.
https://www.koningstrademarks.nl/blog-eng/invented-names/?la...

To choose the strongest type of trademark, ideally you should come up with a brand name that is completely unique, evena fanciful or invented name that hasn’t been used before. Other distinctive types of trademark, not quite as strong as invented marks, include arbitrary or suggestive marks.
https://www.trademarksonline.com.au/blog/2020/8/23/what-is-a...


The name, which may be either an invented name not liable to confusion with the common name, or a common or scientific name accompanied by a trade mark or the name of the marketing authorisation holder

for the identification of the medicinal product: (i) the name of the medicinal product followed by its strength and pharmaceutical form, and, if appropriate, whether it is intended for babies, children or adults. The common name shall be included where the product contains only one active substance and if its name is an invented name;

the scientific name of the stock or stocks followed by the degree of dilution, making use of the symbols of the pharmacopoeia used in accordance with Article 1(5); if the homeopathic medicinal product is composed of two or more stocks, the scientific names of the stocks on the labelling may be supplemented by an invented name,
https://www.wipo.int/wipolex/en/legislation/details/13061

nom du médicament: le nom, qui peut être soit un nom de fantaisie, ne pouvant se confondre avec la dénomination commune, soit une dénomination commune ou scientifique assortie d'une marque ou du nom du titulaire de l'autorisation de mise sur le marché;

le nom du médicament suivie du dosage et de la forme pharmaceutique et, le cas échéant, de la mention du destinataire (nourrissons, enfants ou adultes); la dénomination commune doit figurer lorsque le médicament ne contient qu'une seule substance active et que sa dénomination est un nom de fantaisie;

dénomination scientifique de la ou des souches suivie du degré de dilution en employant les symboles de la pharmacopée utilisée conformément à l'article 1er, point 5); si le médicament homéopathique est composé de plusieurs souches, la dénomination scientifique des souches dans l'étiquetage peut être complétée par un nom de fantaisie,
https://www.wipo.int/wipolex/en/legislation/details/13061

Change in the (invented) name of the medicinal product
Copy of the EMEA letter of acceptance of the new the (invented) name.
https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:C:...

Changement dans la dénomination (de fantaisie) du médicament
Copie de la lettre de l’EMEA portant acceptation de la nouvelle dénomination (de fantaisie).
https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:C:...