Kilotest: Diagnoses of element obsolete violation by HTML element 391 on Mozilla Foundation page

Basics

About the page

• URL: https://www.mozilla.org/en-US/
• Tested 32 days ago on 2026-09-08 at 04:02 by job 260908T0359-xmh
• Summary of results:
  • Rule engines:
    • Called: 12
    • Were able to test: 12
    • Reported any rule violations: 11
  • Violations: 753
  • Violators: 192
  • Issues: 47
• Download the full technical report (JSON)

About the issue

• Why it matters: Page includes obsolete code that the browser may fail to process
• Priority: high
• Related WCAG standard: 4.1
• Reported by 3 rule engines (Alfa + ASLint + QualWeb)
• Violations: 12
• Violators: 12

About the violator

• Tag name: B
• Text: Our mission is to make it easy for people to build with, and collaborate on, open-source, trustworthy AI.
• Start tag: <b>
• XPath: /html/body/div[2]/main[1]/section[1]/div[1]/header[1]/p[1]/b[1]
• Bounding box: x = 272, y = 2602, width = 631, height = 59
• Reported by QualWeb

Take me there

Diagnoses

Here is how rule engines diagnose the element obsolete issue for HTML element 391 of the Mozilla Foundation page.

1. [failed] The webpage uses the element b to control the visual content presentation.

   Rule engine: QualWeb (University of Lisbon)

   Rule: QW-BP10