Topic
indexing
3 guides on this topic.
XML sitemaps: what they do and don't do for indexing
A sitemap is a discovery hint, not an indexing command. What sitemaps accomplish, the limits that matter, and the lastmod mistake that voids the file.
Why isn't my page indexed? A decision tree
Work through the causes in order — blocked, noindexed, canonicalized away, undiscovered, or judged not worth it — and stop guessing.
robots.txt explained: rules, testing, and the classic mistakes
What robots.txt actually controls, what it famously doesn't, how the matching rules work, and the handful of mistakes that block entire sites by accident.