How do I edit what HTML is allowed in comments?

Check the file wp-includes/kses.php then clear your cache before checking.

I added this line:
‘img’ => array(),
I now get an image placeholder, but the image itself isn’t loading

I figured it out, I needed the line:
‘img’ => array(
‘src’ => array(),
‘alt’ => array()),

I followed your advise and added:
‘img’ => array(
‘src’ => array(),
‘alt’ => array()),

It works 100%… Thanks.

Just to make it a bit easier for people who don’t really know what they’re doing (like me till I figured it out) this is the code that I have used:

$allowedtags = array ('a' => array ('href' => array (), 'title' => array ()), 'img' => array( 'src' => array(), 'alt' => array()), 'abbr' => array ('title' => array ()), 'acronym' => array ('title' => array ()), 'b' => array (), 'blockquote' => array ('cite' => array ()),

Hope this helps