Percent-encoded hash (%23) vs fragment (#)

This page demonstrates the difference between # (a fragment delimiter, never sent to the server) and %23 (a percent-encoded literal hash character that is part of the path or query string sent to the server). They look similar in a URL but are entirely different things.

• Fragment link: #real-anchor — browser scrolls to the section below; server only sees a request for /percent-encoded-hash.
• Encoded-hash link: /percent-encoded-hash%23real-anchor — server receives a request for the path /percent-encoded-hash%23real-anchor (a different URL entirely), which returns 404. A crawler that strips %23 as if it were a fragment delimiter would incorrectly record a 200 instead.
• Query param with %23: /query-page/?ref=%23section — the %23 decodes to a literal # in the query value, not a fragment. The server receives ref=#section as a query parameter.