License restrictions control the status of a license file. License files are checked for validity when the PHP server starts. All valid license information is then stored in the memory of the License Registry. Invalid licenses are also registered. This allows the application to check for the type of error that has occurred.
For License File Enforcement files, the Zend Guard Loader checks and then allows or prohibits its running of the encoded file.
For License API Enforcement files, you must program the call for a license lookup using the Zend Guard API and implement your policy based on whether a valid license is available or not.