The convention does not define what a national minority is. States are free to choose which minorities to protect on their territory.
Under the interpretative declaration formulated when Switzerland ratified the Framework Convention, Swiss national minorities are:
"groups of people who i) number less than the rest of the population of the country or canton, ii) are Swiss nationals, iii) have long-standing, solid and lasting links with Switzerland, and iv) are committed to preserving their common identity together, particularly their culture, traditions, religion or language".
Switzerland currently recognises the following groups as national minorities: national linguistic minorities, members of the Jewish communities, Yenish, Sinti and Manouches, whether nomadic or not.
Text of the Framework Convention for the Protection of National Minorities, Council of Europe
Chart of signatures, ratifications and dates of entry into force for the Framework Convention for the Protection of National Minorities, Council of Europe