4 level - < 150 messages
5 level - < 250 messages
6 level - < 500 messages
In case anyone doesn't remember, the "<" sign means "less than," so the text "4 level < 150 messages" means that as long as your messages are fewer than 150, you have the 4th level; as soon as you hit 150 posts, you can no longer be 4th and become the fifth level. The line "5 level - < 250 messages" means that until you have accumulated 250 messages, you are the 5th level, but at the same time, the lower threshold set by the previous condition—that the 4th level is up to 150 messages—is taken into account; thus, people with from 150 to 249 messages inclusive belong to the 5th level. Similarly, we find that people with from 250 to 499 messages belong to the 6th level.
Now let's look at my number of posts - 277. It falls within the range of 250 to 499. Therefore, I should have the 6th level, just as you actually do, Loken.
As for the phrase about the dashes, then, firstly, the threshold for the 14th level is unknown; secondly, about half a year ago, the rank system was discussed and it was decided to set it exactly as written in the help section, and since the system has changed but the help section hasn't, one can conclude that this is a bug.
Added after 2 minutes
/topic/3307/ - the previous topic on this matter. Now, alas, it is closed, so I am writing here.

