liittymisiin
Liittymisiin is a Finnish word form that can arise from the base word liittymä, which has several related meanings, including connection, interface, and subscription, as well as from liittyminen, meaning joining or affiliation. As a grammatical form, liittymisiin appears in contexts where there is movement toward joining or becoming a part of something, and its exact interpretation depends on the surrounding words.
In everyday and technical Finnish, liittymä commonly refers to a subscription or account, for example in telecommunications
The form is part of Finnish inflection, and its use is typical in formal, administrative, or policy