The classification of shares in PetroChina and Berkshire Hathaway's ownership

The government's 90% shares and our 10% shares are classified differently, causing confusion. We had to report our ownership even when we only had 1% economic interest. Despite this, we're satisfied with our 1.3% ownership and think PetroChina is well-run. It's a major enterprise with large gas reserves. Few people realized its size compared to other oil companies. We didn't have any contact with management but made our decision based on their publicly available annual report.