There are two kinds of symbols that appear next to the topic subject:
- Orbs are colorful glossy dots on the left side of a topic's subject. They describe what kind of topic you are looking at: green topics are normal discussions, orange ones are special “question / problem topics” (described above), blue are topics linked with news / reviews' comments while red are special announcements by the GOG.com Team. Don't worry, you will get used to it sooner than you know :);
- Icons and labels, shown on the right side of a topic's subject, indicate the topic's status. They can point out closed topics, threads with new replies to your posts or solved question / problem discussions.
There should be a forum key with all this information on the bottom of the topics list. If you've removed it, you can always bring it back using the “My Settings” option on the forums.