The purpose of the thread is explained in the first post. That's the intent of the thread as stated by the thread starter. If the posts pertain to that in some way, then the posts are "on topic". If they veer away from the stated intention of the thread, then they're off topic. Threads where the discussion veers sharply and permanently away from the intention are called "hijacked", and can be closed down for that reason. Members who don't refrain from hijacking threads are warned, and can ultimately be banned for bad forum behaviour.
Again, if you want to know what this thread is about, refer to the initial post. Please keep all posts on or near that topic.
Again, if you want to know what this thread is about, refer to the initial post. Please keep all posts on or near that topic.