Even public railway lines built for constructional or industrial purposes were counted as Kleinbahnen.
The concept was defined in the Prussian Kleinbahn law of 28 July 1892, that was designed to encourage the construction of local railway lines by private companies.
In several former German states such as (Mecklenburg, Oldenburg and Baden) the concept Kleinbahn was partially adopted for lines of limited length and light construction.
In everyday speech the term Kleinbahn is widely used as a synonym for narrow gauge lines or garden railways.
The construction and operation of Kleinbahnen were carried out to less stringent requirements, e.g. tracks were laid in a gravel rather than a normal ballast bed, and usually by private companies, which nevertheless in many cases involved substantial participation by the state, the province or local communities.