# Canonical Tag/Rel=Canonical

##### Summary

This glossary contains definitions of technical and marketing terms referenced across DAO.AD documentation.

##### Definition

A canonical is an HTML attribute that refers to a site owner’s preferred or master version of a web page. Using a canonical tag helps to consolidate duplicate issues in a search engine’s index if the content is the same or similar across multiple pages. Canonical tags can be honoured or ignored by search engines depending on the reason they’re used.