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filter is not described

img_caption_shortcode_width filter-hook . WP 3.7.0

Filters the width of an image's caption.

By default, the caption is 10 pixels greater than the width of the image, to prevent post content from running up against a floated image.

Usage

add_filter( 'img_caption_shortcode_width', 'filter_function_name_621', 10, 3 );
function filter_function_name_621( $width, $atts, $content ){
	// filter...

	return $width;
}
$width(int)
Width of the caption in pixels. To remove this inline style, return zero.
$atts(array)
Attributes of the caption shortcode.
$content(string)
The image element, possibly wrapped in a hyperlink.

Where the hook is called

img_caption_shortcode()
wp-includes/media.php 1577
$caption_width = apply_filters( 'img_caption_shortcode_width', $width, $atts, $content );

Where the hook is used (in WP core)

Does not used.