The Lilium moderator,
@pardalinum, can answer your questions about the advisability of adding these cultivars to the database.
As for the foreign diacritical marks, they are not recognized by our system. Consequently, the names probably will be misalphabetized and they will not come up in a search for anyone not using the diacritical marks. The best option is to omit the marks in the cultivar name and add the name with the marks as an also-sold-as name. That way, it will come up in the search results whether people use the marks or not.
