Package Structure · E-NEST

Severe HTML nesting errors

Some HTML tags in your book are nested incorrectly (e.g. a paragraph inside another paragraph), which can break rendering.

Error: Severe HTML nesting errors
Category: Package Structure
Severity: error
Auto Repair: Supported
Rule ID: E-NEST
Affected: KDP=reject, Apple=reject, Google=reject, Kobo=warning

Why this happens

• Unclosed <p> or <div> causing the next block to nest illegally.
• Block elements placed inside <p>, <span>, or <a> by a visual editor.
• List / table structure broken (li outside ul/ol, td outside tr).
• Copied HTML fragments merged without a normalizing pass.

How platforms treat it

How Cermify detects it

1. Parse each XHTML content document with a strict XML/HTML nest checker.
2. Record illegal parent/child combinations and unclosed elements.
3. Prioritize errors that prevent well-formed XML or known Kindle breakages.
4. Surface file + approximate location for repair.

Automatic repair

Cermify can close or split common illegal nests (e.g. p-in-p) when the intent is clear. Deeply corrupted trees may require exporting a clean chapter from the source tool.

Manual fix

1. Open the cited chapter and validate nesting in an XML-aware editor.
2. Close or split overlapping paragraphs and divs.
3. Move block content out of inline parents (p, span, a).
4. Re-run epubcheck until nesting errors clear.

Examples

Paragraphs must not wrap other paragraphs.

Incorrect

<p>Opening paragraph
<p>Second paragraph nested illegally</p>
</p>

Correct

<p>Opening paragraph</p>
<p>Second paragraph nested illegally</p>

FAQ

How is this different from E-RSC005?

E-NEST focuses on structural nesting. RSC-005 also covers invalid attributes and CSS; both can appear on the same file.

Will browsers hide the problem?

Browsers forgive bad HTML; EPUB/XHTML and Kindle pipelines often do not. Fix nesting for store upload.

Can I convert everything to divs?

Prefer semantic headings and paragraphs. Blind div soup can still nest illegally and hurts accessibility.

Related errors

• Invalid HTML/CSS construct (RSC-005 family)
• Non-UTF-8 encoded content file

References

• XHTML content document constraints
• Cermify Rule Set kdp-epub-2026-07