Exclude directories & subdirectories from validation in Eclipse

Question

How do I exclude a folder AND its sub-directories from validation in eclipse? I know that you can right click on a folder in Package Explorer and select Exclude Validation,

Answer 1

For those PHP developers who coding in Eclipse Mars.

1. Right click on folder.
2. choose "Use As Library Folder"

For example in laravel framwork, you can exclude /vendor, /storage and /node_modules folders from eclipse validation.