If you're editing a record in Cataloguing you can save it to your PC for later editing. To open a record you've previously saved to your PC:
It might be good practice to download the latest version of a record from the database and edit that, rather than edit a record that you downloaded and saved to your PC some days or weeks before. If the record has been amended since you downloaded it to your PC then the 005 fields will no longer be the same and your update will be rejected.