title: Specify custom canonical URL in WordPress Post
body: <p>We operate 1000's of websites, most of them are are made for specific sports events. Currently we have our writers write to all of them specifically for unique content.</p>
  
  <p>However we have 2 major sites that cover all events in their verticals; and we would like to start syndicating content to the minisites, from these major sites.</p>
  
  <p>To maintain best practices in Google's eyes, we would have to specify the original source of the article via the rel=canonical tag - however our current plugin AIOSEO (All-in-One SEO) doesn't support specifying canonical tags on a post, or page basis.</p>
  
  <p>Is there a way to create such a function?</p>