Summary

xsd validation fails on etc/adminhtml/system.xml files that contain <comments> below <field> items.

Examples

Launch PHPStorm and setup xsd validation, as per Magento devdocs.
Browse to a file containing a <comment> as a child to a <field>. Theres plenty to choose from

Check out the definition in the xsd file vendor/magento/module-config/etc/system_file.xsd

Notice that comment is not defined as a string.
Verify that on Experience League (https://experienceleague.adobe.com/en/docs/commerce-operations/configuration-guide/files/config-reference-systemxml), using <comment> as a child of <field> is supported. It is used extensively throughout Magento backend.

Proposed solution

Its an annoyance. Its been around for years. Its time to fix it.

Update type of comment to be string.

Release note

XSD validation now accepts <comment> entries as children of <field> entries in system.xml config files.

Triage and priority

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.