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HTML Guide

Free site validation

Find out what web pages on your sites are affected by HTML issues.

Bad value X for attribute “id” on element “pattern”: Not a valid XML 1.0 name.

A <pattern> element has been found with an invalid ID. Check the format of the ID and ensure it does not start with a digit, full stop (.) or hyphen (-).

The <pattern> element is used within <svg> elements, which use XML 1.0 syntax. That syntax specifies that valid IDs only include designated characters (letters, digits, and a few punctuation marks), and do not start with a digit, a full stop (.) character, or a hyphen-minus (-) character.

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