Configure include paths
Include paths are used for holding libraries, that is, third-party code that is used for completion and reference resolution in some functions/methods that use file paths as arguments, for example, require() or include().
Note that the files added via include paths are not meant to be edited within the scope of your project. If you have the existing code that you need to access and modify from within several projects, consider adding it via an additional content root.
Configure include paths
In the Settings dialog (Control+Alt+S), click PHP.
On the PHP page that opens, configure the list of include paths on the Include path tab:
Use
and 
to add and remove paths.Use
and 
to reorder the items in the list.Click
to sort the paths alphabetically in the ascending order.
