In addition to defining your own file filters, there are six predefined file filters that can be applied to jobs.
Two of the predefined filters, Default and Invalid Characters, are applied to all jobs by default. However you can deselect a predefined filter for a specific job. Only the Default filter can be modified; none of the predefined file filters can be deleted.
In addition to these predefined filters, there are file types that are automatically excluded from a watch set for all job types.