When you add multilingual support for Process Central configuration, forms and tasks, you create a properties file for each language you want to support. There is one default file and other files with language codes:
MyPropertiesFile.properties:
This is typically the default file for en-US.
MyPropertiesFile_ISO639Name.properties:
For each language, you must add an underscore and a ISO 639.2 code for the representation of names of languages. Add the _language code and optional country code to the default file name. Country codes are the upper-case, two-letter codes as defined by ISO-3166.