Formal

adjective (1)

1. following or according with established form, custom, or rule
2. relating to or involving the outward form, structure, relationships, or arrangement of elements rather than content
3. made or done in an official and usually public way
4. done in due or lawful form
5. characterized by punctilious respect for form : methodical
6. rigidly ceremonious : prim
7. suitable for serious or official speech and writing
8. having the appearance without the substance
9. existing or being something in name or form only
10. belonging to or constituting the form or essence of a thing