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filter is not described

post_thumbnail_html filter-hook . WP 2.9.0

Filters the post thumbnail HTML.

Usage

add_filter( 'post_thumbnail_html', 'filter_function_name_3427', 10, 5 );
function filter_function_name_3427( $html, $post_id, $post_thumbnail_id, $size, $attr ){
	// filter...

	return $html;
}
$html(string)
The post thumbnail HTML.
$post_id(int)
The post ID.
$post_thumbnail_id(string)
The post thumbnail ID.
$size(string/array)
The post thumbnail size. Image size or array of width and height values (in that order).
Default: 'post-thumbnail'
$attr(string)
Query string of attributes.

Where the hook is called

get_the_post_thumbnail()
wp-includes/post-thumbnail-template.php 183
return apply_filters( 'post_thumbnail_html', $html, $post->ID, $post_thumbnail_id, $size, $attr );

Where the hook is used (in WP core)

Does not used.