Translations:New Template System in LS3.x/117/en
From LimeSurvey Manual
Inheritance tips
As explained before, the "add" keyword can refer to a file being in one of the mother theme. So you can "add" a file in this section, and still not having this file in your theme, but in one of its parents theme. The engine will look into all its parent themes and will use the first one it finds. If it can't find the file, and debug mode is on in config, and js frontend debug mode is on in global setting, a message in console will warn you. Eg: if we add in a my_theme: <add>css/unexisting.css</add>, in the console we'll see: