Updated versions of our national specifications published

Updated versions of our national digital preservation specifications have been published:

• Metadata Requirements and Preparing Content for Digital Preservation (v1.7.3), defines how content is transferred to the preservation service and what metadata it should contain.
• File Formats (v1.9.0), describes the file formats acceptable in our preservation service.
• Service Interfaces (v2.2.0), defines the machine readable interfaces of our preservation service.