"regional or minority languages" means languages that are:
traditionally used within a given territory of a State by nationals of that State who form a group numerically smaller than the rest of the State's population; and
different from the official language(s) of that State
Influence of number of speakers
There are many cases when a regional language can claim greater numbers of speakers than certain languages which happen to be official languages of sovereign states. For example, Catalan (a regional language of Spain and France, albeit official in Andorra) has more speakers than Finnish or Danish. In China, Wu, spoken in southern Jiangsu and northern Zhejiang by more than 90 million speakers, can claim more native speakers than French, and Cantonese, a regional language of Guangdong and nearby areas in China with more than 60 million local and overseas speakers (North America, parts of Malaysia), outnumbers Italian in number of speakers. Subgroups and dialects of the Min group have over 70 million speakers, mainly in Fujian and in nearby Taiwan, but also in the Southeast Asian countries of Malaysia and Singapore.
Relationship with official languages
In some cases, a regional language may be closely related to the state's main language or official language. For example:
Low Saxon (also referred to as Low German), an officially recognized regional language in Germany and The Netherlands, the direct descendant of Old Saxon, in some people’s opinion two languages divided by today’s Netherlands-German border on account of Dutch influences in the west and German influences in the east; most closely related to Dutch and Frisian, more distantly to German.
Leonese, a regional language of Leonese Kingdom, recognized in Castile and León (Spain), and in Miranda (Portugal) as Mirandese, close to Spanish and Portuguese.