How to render html tags in image caption

In order to render html tags, like <br>, <i>, <b>, <em> used in image caption of tt_content is required to add the following lines of code in TSref template:

tt_content.image.20.caption.1.1 {
 parseFunc { 
allowTags = br,span, i, em, b 
denyTags = *
 } 
htmlSpecialChars = 0 
}