The main purpose of this script is to help users scroll down over uninteresting content faster. It does so:
If a post has any external hyperlinks, a list of the respective domain names is added next to the post folding toggle. Clicking any of these domain names toggles their 'blacklisted' state on or off. The blacklist is stored only in the local user script settings.
The changes do not apply immediately, the page must be reloaded to in order see them.
Any post with hyperlinks leading only to blacklisted domains will be folded by default, with only their header visible. It can still be viewed by revealing the post manually. Links to blacklisted domains will be of a lighter color in order to emphasize other, non-blacklisted links in the post.
Manual folding/revealing of individual posts is not persisting and upon the next page load the posts will be either visible or folded based on the rules above.
Thread Tools menu has buttons to toggle all or unread posts that have been auto-hidden.