Detailed answer
A canonical link identifies a preferred URL for substantially duplicate content.
Use a valid public URL representing the same content, and keep it aligned with internal linking and sitemaps. It is a hint rather than a mechanism for merging unrelated pages. Update development URLs during migration.
Example
<link rel="canonical" href="https://forum.htmlcoderunner.com/topic/html-label-for/">
Understanding the behavior
A canonical link identifies the preferred version of substantially duplicate content. It is a signal, not a guaranteed instruction, and should agree with internal links, redirects and sitemap URLs. Distinct pages should normally retain their own appropriate canonical URLs.
Practical implementation notes
Do not canonicalize every page in a paginated discussion list to page one. Check that the preferred URL returns useful public content and does not redirect to an unrelated page or require a login.
How to check it
Inspect the canonical destination and confirm it returns the same public content.
Expected result
The preferred URL is specific to that content, not the homepage.
Watch out: Do not canonicalize every topic to the homepage.
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