Error guide

Element not allowed in JATS XML

The element not allowed message appears when an XML child sits outside the content model defined by the JATS XSD. The document may be well-formed —meaning it parses correctly as XML— and still fail schema validation because the semantic structure does not match what JATS Archiving expects.

This error is among the most frequent in journals migrating from Word or PDF, where content is organized visually but not according to standard rules. Understanding the message lets you fix the root cause instead of applying random patches.

What the error means

Each JATS element declares which children it may contain, in what order, and how many times. The validator compares your XML against that model. If you insert, for example, a <p> where only <title> is expected, or place <table-wrap> directly inside <abstract>, it reports the child element as not allowed and points to the approximate line.

The error almost always refers to the child, not the parent. Read the message to identify which tag is misplaced and consult the immediate container element in the JATS 1.3 Archiving specification.

Example 1: loose paragraph in body

Incorrect:

<body>
  <p>Paragraph without a containing section.</p>
</body>

In JATS Archiving, the <body> of a research article expects <sec> sections, not direct paragraphs.

Correct:

<body>
  <sec sec-type="intro">
    <title>Introduction</title>
    <p>Paragraph inside a valid section.</p>
  </sec>
</body>

Example 2: section without title

Incorrect:

<sec>
  <p>Text without a section title.</p>
</sec>

In many contexts, <sec> expects a <title> before narrative content.

Correct:

<sec>
  <title>Methods</title>
  <p>Section text.</p>
</sec>

Example 3: table inside abstract

Incorrect:

<abstract>
  <p>Study abstract.</p>
  <table-wrap id="tbl1">
    <table>...</table>
  </table-wrap>
</abstract>

<abstract> does not admit tables or figures in the standard Archiving profile.

Correct: Move the table to <body> within the appropriate results section.

Frequent causes in editorial production

Source	Typical pattern
Word conversion	Mis-mapped floating blocks
Copy/paste from another article	Elements from wrong context
Embedded HTML	Non-JATS tags (`div`, `span`)
Supplementary material	Files in wrong location

If the validator mentions HTML elements, replace them with JATS equivalents (<bold>, <italic>, <xref>) or remove unsupported markup.

Step-by-step diagnosis

Open the file in the JATS validator.
Jump to the line indicated in the report.
Identify the parent element of the reported child.
Consult which children that parent admits in JATS Archiving.
Move, rename, or remove the child to match the model.
Revalidate until the error is cleared.

For cascading errors, fix the first one: subsequent errors often disappear when the parent structure is restored.

Relation to other errors

Element not allowed often appears alongside invalid document structure when mandatory blocks such as <front>, <body>, or <back> are missing. Review the complete hierarchy if you receive multiple structural errors.

See also common JATS errors for an overview of the 15 most frequent patterns.

Prevention in your editorial workflow

Use XML templates with predefined <sec> structure.
Validate each article as it enters the issue, not at the end.
Train the conversion team on the three article regions: front, body, back.
Document approved exceptions for special article types (editorial, letter).

If structural errors recur, consider editorial validation or JATS XML production to normalize the workflow.

Conclusion

The element not allowed error does not indicate corrupt XML: it indicates a mismatch between the structure you wrote and what JATS requires. With the validator, the parent element specification, and a coherent template, correction is systematic and repeatable issue after issue.

Validate your file in the JATS validator and explore other error guides for related diagnostics.