HTML Checking for Large Sites
Rocket Validator automatically checks your pages on the W3C Validator.
Attribute “<” not allowed on element “X” at this point.
Check the syntax of the affected tag, it’s probably malformed and a <
character inside has been interpreted as an attribute.
For example, this code might cause this issue:
<!-- Malformed img tag -->
<img src="photo.jpg" alt="smiling cat" < />
<!-- Fixed img tag -->
<img src="photo.jpg" alt="smiling cat" />
Related W3C validator issues
The attribute displayText
is not allowed on <span>
elements.
This issue is commonly caused by an old integration of ShareThis via Drupal or other CMS - the old code used invalid attributes like displayText
, st_url
and st_title
which were later changed to HTML5 custom data attributes.
Learn more:
- [ShareThis: how to migrate legacy buttons(https://sharethis.com/support/installation/migrate-from-sharethis-legacy-buttons-to-inline-buttons/)
- Drupal: W3C validator issues on st_url
- MDN: using data attributes
The <table>
element does not accept a height
attribute. Use CSS instead.
The attribute st_title
is not allowed on <span>
elements.
This issue is commonly caused by an old integration of ShareThis via Drupal or other CMS - the old code used invalid attributes like displayText
, st_url
and st_title
which were later changed to HTML5 custom data attributes.
Learn more:
- [ShareThis: how to migrate legacy buttons(https://sharethis.com/support/installation/migrate-from-sharethis-legacy-buttons-to-inline-buttons/)
- Drupal: W3C validator issues on st_url
- MDN: using data attributes
The attribute st_url
is not allowed on <span>
elements.
This issue is commonly caused by an old integration of ShareThis via Drupal or other CMS - the old code used invalid attributes like displayText
, st_url
and st_title
which were later changed to HTML5 custom data attributes.
Learn more:
- [ShareThis: how to migrate legacy buttons(https://sharethis.com/support/installation/migrate-from-sharethis-legacy-buttons-to-inline-buttons/)
- Drupal: W3C validator issues on st_url
- MDN: using data attributes
An attribute could not be parsed from the HTML input, probably due to a typo. Check this guide for a related HTML issue.
An invalid attribute has been found on an element. Check the affected tag to ensure attributes are well-formed, and if they are you can consider using custom data attributes.
Learn more
Quote characters used for attributes can use either single quotes ('
) or double quotes ("
), and they must be properly matched, for example:
<p class="news">...</p>
A common cause for this issue is forgetting to use the equal sign (=
), so the HTML parser wrongly believes the quote forms part of the attribute name, for example:
<p class "news">this is wrong</p>
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