John Mueller of Google had an interesting reply to a question around linking to a page without a rel canonical attribute on it, and that page has URL parameters on it for necessary tracking purposes. John said "if the parameter URLs are few, we can keep up and probably map to the canonicals. If it's a ton of parameter URLs, we could lose track."
This was over Twitter, so let me embed the questions and John's response:
I should note this is a large member website, with a shop. They are on 2 different CMS platforms. The non-canonical is a parameter used for tracking that must be in place. The link in question is on the member side, pointing to the shop. This is the only link to the shop pages.
— John Morabito (@JohnMorabitoSEO) May 24, 2021
It depends ... If the parameter URLs are few, we can keep up and probably map to the canonicals. If it's a ton of parameter URLs, we could lose track. That said, if it's important to you, I'd try to make it clean - small things add up too.
— 🍌 John 🍌 (@JohnMu) May 25, 2021
I am not sure I can explain it better than John Morabito did here but in short, they want to add a link from a site's home page but that link is not a canonical URL but a URL with URL parameters for tracking purposes. Will that confuse Google, adding a non-canonical URL from a home page...
John said "it depends" and it depends on how many URL parameters are in the URL. He said keep it as short and clean as possible.
In any event, this shows me why canonical link attributes are important in these situations. But when you link to a location without it, that can be confusing for Google. Make sure you give Google consistent signals.
What do you all think of this situation? I suspect this is not so uncommon.
Forum discussion at Twitter.