Search engines may index page URLs with the 'pk_vid' cross domain URL parameter added, for example in these search results:

Seen at https://www.ecosia.org/search?q=Managing+processes+via+CLI%3A+not+supported+matomo

Could we maybe prevent this parameter from appearing in indexed URLs?
Not sure what would be the best solution for this for users, and whether there is even a simple solution... for example:

• Users could define canonical html meta tag, but that's some manual work. (in the plugins.matomo.org example above, we don't yet define the canonical url which could explain the issue)
• There is a tool in google console to add URL to exclude: https://www.google.com/webmasters/tools/crawl-url-parameters (this may only be available in Google)
• maybe we could even in the cross domain code remove the URL parameter if we detect a search engine bot? eg. https://stackoverflow.com/a/33941034/3759928

(then we might document what we did in the Cross domain FAQ: https://matomo.org/faq/how-to/faq_23654/)