Database.com Metadata API Developer's Guide - Salesforce.com

Metadata TypesPermissionSetFieldenablednameField TypebooleanstringDescriptionRequired. Indicates whether the permission is enabled (true)or disabled (false).Required. The name of the permission.Declarative Metadata Sample DefinitionWhen adding or changing a permission set, you don't need to include all permissions—you only need to include the permissionsyou're adding or changing.Grants all rights needed for an HR administrator to manageemployees.HR AdministrationSalesforceJobApps__RecruitingtruetrueAPIEnabledtruetruetruetruetruetrueJob_Request__ctrueJob_Request__c.Salary__ctrueJob_Request_Web_FormtrueSend_Email_ConfirmationtrueJob_Request__cAvailableRecruiting.DevManagertrueThe following is an example package.xml manifest used to retrieve the PermissionSet metadata for an organization. Whenyou retrieve permission sets, you should also retrieve the related components with assigned permissions. For example, to retrieveobjectPermissions and fieldPermissions for a custom object, you must also retrieve the CustomObject component.Job_Request__c129