Labor unions can be classified into the following three types; however, teachers can only organize and join the labor unions referred to in Subparagraphs 2 and 3:
1. Corporate union: a labor union organized by employees of the same factory or workplace, of the same business entity, of enterprises with controlling and subordinate relationship between each other in accordance with the Company Act, or of a financial holding company and its subsidiaries in accordance with the Financial Holding Company Act,
2. Industrial union: a labor union organized by workers in the industry, and.
3. Professional union: a labor union organized by workers with the same professional skills.
Organizational district of a professional union in accordance with Subparagraph 3 of the preceding paragraph shall be limited in the municipal city or county (city) where it locates.