What are forum ranks?
Go to Forums.
Select the Forums tool from the Tool Menu of your site.
Click Ranks.

The Ranks button is located below the name of the course site.
Click Add Rank.

Create a Rank Name.

Select Rank Type.

There are two options for the type of Rank. A site member can be ranked manually or based on post count threshold.
Upload a Rank Image. (Optional)

Click browse to retrieve a saved image. The Rank Image is restrained to 35 x 35 pixels and the image must be less than 100KB.
Click Update.

Click Update to finish Rank or Cancel.