Translations:Localization/2/en
From LimeSurvey Manual
One is in the installation directory where built-in messages to the PHP code are stored in language specific files. These must be translated and installed by the system administrator. Only then is the language available for the administrative interface, for some basic buttons, and built-in messages seen by survey participants. Normally, a survey developer would not have access to edit these translations, but only select them.