Note:
The Validation Properties page is not applicable for PHP projects.
The Validation Properties page allows you to specify which validators should run for the project, and whether validation should occur automatically when resource updates are written to the project. The available validators are based on the types of resources in your project. By default, validators are automatically run when you save resources in a Web project. If you do not want validators to run automatically when you save these resources, enable the Override validation preferences option and disable the Run validation automatically when you save changes to resources option.
To access the Validation Properties page, right-click a PHP project in PHP Explorer view and select Properties | Resource -or- select the project and from the menu bar go to Project | Properties | Validation Properties.