Here's a guide on the various codes that can be seen when you monitor a link:
Not Linking -
There is no link from this page to the domain you are monitoring.
Follow (#) -
This is how many links are marked as active follow links. This can include image links as well!
No Follow -
This is how many links are marked as no follow.
Error 301 -
This means that there is a page re-direct when someone clicks on this link.
Error 404 -
This means the page cannot be found, thus there is no active link. The typical trigger for Error 404 is when a website or its content has been removed or moved to another URL.
This means that your link is active.
While in Link Monitoring, you can find these definitions by hovering over "Linking URL Status."