What are the different errors & statuses of links?

There are Statuses of links & their meaning.

• OK (Ok) - We found the backlink with exact match, rel tag & anchor text were also correct.
• Present (PR) - We found the backlink or the domain of the backlink but there might be some issue. Check the error field for more info. In this case, the error field might contain
• Absent (AB) - We checked the link_from page and didn't find the backlink
• Error (ER) - We checked the the link_from and we found some error, check Error code field for more details
• Not Checked (NA) - We haven't been able to check the backlink either because it was added before the time when the list is expected to be crawled.

There are multiple errors that can come. These are the error and there reasons

1. link_from invalid - from_link is invalid, redirected, expired, etc (4xx, 5xx & similar type of error codes lies in this).
2. Rel_tag not matched - The link is present but the rel_tag is mismatched.
3. Anchor text not matched - The link is present but the anchor text is mismatched.
4. Page 4xx - Unauthorized access. The server of the link_from page is not allowing us to access the page because it requires some type of authorization.
5. Page 5xx - The server didn't respond
6. Anchor text almost matched - The anchor text didn't match exactly, but almost matched
7. Rel tag found - You didn't give us any rel tag and we found one, we mentioned it in Error field as well
8. Anchor Text Found - You didn't give us any anchor text and we found one, we mentioned it in Error field as well
9. Domain present, Exact link not matched - We couldn't find the link_to on link_from page but the domain was present
10. link_to not in link_from - We couldn't find the link_to on link_from page and the domain was not present as well
11. Internal error. Note able to render site. - The site blocked the crawler and didn't render it
    
12. Link Timeout - The link_from page took too much time to load.