In the Anchors section of Site Explorer, you may sometimes notice that a certain anchor is missing from our reports when doing a manual check of the page in question.
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If there are duplicate links on a page, we only consider one of them.
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Here's a scenario to illustrate this:
There are 3 different anchor texts linking to Ahrefs on a page.
1. Ahrefs
2. https://www.ahrefs.com/
3. www.ahrefs.com
However, 1. and 2. link to https://www.ahrefs.com, while 3. links to http://www.ahrefs.com.
Only two distinct links are used.
As only links with distinct URLs are considered, 1. and 2. are considered duplicate links. Hence, one anchor will be missing in your report.