Just my opinion but as a starting point for the argument...

  * 20 years from date of first publish (renewable up to CAP? 50 years)
  * Must remain available every year
  * 10 year renewal blocks with massive registration fee increases
  * Compulsory maximum license fee cap (can offer for less) in the laws

Note this is not TRADE MARK; trade marks are _consumer protection_ related to 'brand ownership'.