Kilotest: Diagnoses of element closure invalid violation by HTML element 0 on Clean Air Task Force (CATF) page

Basics

About the page

• URL: https://www.catf.us/
• Tested 3 days ago on 2026-10-07 at 19:52 by job 261007T1941-eso
• Summary of results:
  • Rule engines:
    • Called: 12
    • Were able to test: 12
    • Reported any rule violations: 12
  • Violations: 697
  • Violators: 328
  • Issues: 52
• Download the full technical report (JSON)

About the issue

• Why it matters: Page contains invalid code
• Priority: high
• Related WCAG standard: 4.1
• Reported by 1 rule engine (Html Checker)
• Violations: 2
• Violators: 2

About the violator

• Tag name: HTML
• Text: [not applicable]
• Start tag: <html class="js" lang="en">
• XPath: /html
• Bounding box: x = 0, y = 0, width = 1920, height = 7933
• Reported by Html Checker

Diagnoses

Here is how rule engines diagnose the element closure invalid issue for HTML element 0 of the Clean Air Task Force (CATF) page.

1. Stray end tag head. Extract: ></script></head> <bo

   Rule engine: Html Checker (World Wide Web Consortium)

   Rule: Stray end tag head.