WordPress at a glance
filter is not described

img_caption_shortcode filter-hook . WP 2.6.0

Filters the default caption shortcode output.

If the filtered output isn't empty, it will be used instead of generating the default caption template.

Usage

add_filter( 'img_caption_shortcode', 'filter_function_name_3729', 10, 3 );
function filter_function_name_3729( $output, $attr, $content ){
	// filter...

	return $output;
}
$output(string)
The caption output.
Default: ''
$attr(array)
Attributes of the caption shortcode.
$content(string)
The image element, possibly wrapped in a hyperlink.

Where the hook is called

img_caption_shortcode()
img_caption_shortcode
wp-includes/media.php 1537
$output = apply_filters( 'img_caption_shortcode', '', $attr, $content );

Where the hook is used (in WP core)

Does not used.