Setting multiple validation rules on a text field/date field

Setting multiple validation rules on a text field/date field

Let's say I have a text field where they are expected to input some kind of ID.

To minimize typos, we are thinking about introducing the following validation rules:
- Entry has to start with "DLM-"
- Entry also has to be 15 characters long

Right now it's easy to set either of the above 2 validation rules individually, but it's not clear how to enable both. 

Also curious how to apply something similar for dates (i.e. date has to be before certain date range, but not past a certain point - e.g. year before 1998, but not before 1900).