Greetings All :slight_smile:
I have not seen this posted or mentioned anywhere here on WPMU and if I missed it please forgive me - but I wanted to share this potentially devastating development with you.
I noticed that we started to lose pages in Google - in fact we were slowly being delisted from Google and other Search Engines and I had not a clue as to why.
So I started to do my research and found out where the problem is for all MU sites that use canonical domains (i.e. *.domainname.com) since I am guessing around WordPress 2.9+
I started using SEO Doctor checking all of our WP based Sites (robots.txt, index meta tag, even the rare x-robots-noindex HTTP header) and everything seemed to be perfect by SEO Doctor with one exception that claimed "Page is not indexable because this page has a canonical URL"
Today I discovered the root of the problem - I am guessing since around WordPress 2.9 ( I believe since that is when I first noticed delisting starting ) and found the "rel canonical meta tag" was introduced and added automatically for all dynamic pages.
This was in fact the case with our sites and the solution is to just add this to your theme functions.php:
and it should fix you right up :slight_smile:
I would suggest that possibly all WPMU themes should have this added by default to their functions.php file to circumvent this currently built in SEO disaster :slight_smile: