To create a thread with a limit of hiding posts after 1500, you can follow these steps:
1. Go to the "General Questions" section of the forum.
2. Click on the "New Thread" button to create a new thread.
3. Give your thread a title and write your post in the text box.
4. Scroll down to the "Thread Management" section.
5. In the "Maximum Posts to Show Per Page" field, enter the value "1500".
6. In the "When to Hide Posts" field, select "After Maximum Posts Per Page".
7. Click on the "Submit" button to create your thread.
Now, your thread will only show the first 1500 posts, and any additional posts will be automatically hidden from view. Users can still see hidden posts by clicking on the "Show Hidden Posts" button.