Definition
The definition of plain language in Finland is based on a comparison to common language. The Research Institute for the Languages of Finland defines common language as follows:
Common language is a language form shared by various age and occupational groups within a linguistic community. Its outward form is in accordance with the standards of the written language, it uses a vocabulary that is known to be commonly understood (or at least it explains the special terms used) and has a simple sentence structure.
The Plain-Language Centre’s Definition of plain language from 2001:
Plain language has been adapted in its content, vocabulary and structure so that it is easier to read and understand. Its purpose is to help people that have difficulties in reading and/or understanding the common language.