Excluding files from projects
Sometimes you might need to exclude a single file from your project, so that it will be ignored by inspections, code completion, and so on. This is done using the Override File Type action.
When a file is marked as plain text, PhpStorm does not use it anymore for code completion and navigation. Such file is shown as plain text in the editor, and is marked with a special icon 
in the Project tool window.
The reverse action is also available: you can return a file to its original type by using the Mark as <file type> action.
In the context of a PHP project, you can also exclude entire PHP archives (phar files) to prevent multiple declaration conflicts between classes in a phar archive and the corresponding classes in the installed vendors directory.
Mark a file as plain text
In the Project tool window, select the desired file.
From the context menu of the selection, select and then select Plain Text from the Choose File Type list.
Mark a file with its regular type
In the Project tool window, select the desired file marked with
icon.From the context menu of the selection, choose :
Exclude files and folders by name patterns
In the Settings dialog (Control+Alt+S), click Directories.
In the Exclude files field, type the masks that define the names of files and folders to be excluded, for example,
*.min.jsorlib. Use semicolons as separators.If the name of a file matches any of these patterns, the file is treated as excluded.
If the name of a folder matches a pattern, all the files in this folder and in its subfolders are excluded.
Exclude a phar archive from a project
In the Project tool window, select the required phar archive and choose Exclude phar from project from the context menu of the selection.