I have noticed that some websites prefix the titles of their links with blocked::.
For example:
<a href="http://www.a-url.com" title="blocked::http://www.a-url.com">www.a-url.com</a>
I have questions about how this affects browsers and search engines:
I have never seen this kind of syntax, and I'm quite sure it has no standardized meaning.
However, interestingly, Microsoft Outlook marks the href part of links this way as a security feature:
When you receive an HTML message, links in it may not work or the File, Open dialog will open, asking to associate an executable file with the link.
Looking at the source, you'll see the URL is prefixed with BLOCKED::, like this:
<A title=http://office.microsoft.com/ href="BLOCKED::http://office.microsoft.com/">Office Online</a>
This is a security feature in Outlook and may happen when URLs are copied from one email message and pasted into another message.
My guess would be that those links are actually copy+pasted links from a Microsoft Office document, and the title
element somehow gets garbled in the process.