Can you indicate which tag(s) you were using and in what field?
The tags that are currently allowed in version 7.4.3 are the following:
function allowed_html_tags() {
return array(
'a' => array(
'href' => array(),
'title' => array(),
'class' => array(),
'data' => array(),
'rel' => array(),
),
'abbr' => array(
'title' => array(),
),
'acronym' => array(
'title' => true,
),
'b' => array(),
'blockquote' => array(
'cite' => array(),
),
'br' => array(),
'cite' => array(
'title' => array(),
),
'code' => array(),
'del' => array(
'datetime' => array(),
'title' => array(),
),
'dd' => array(),
'div' => array(
'class' => array(),
'data' => array(),
'style' => array(),
),
'em' => array(),
'dl' => array(),
'dt' => array(),
'em' => array(),
'h1' => array(),
'h2' => array(),
'h3' => array(),
'h4' => array(),
'h5' => array(),
'h6' => array(),
'hr' => array(),
'i' => array(),
'img' => array(
'alt' => array(),
'class' => array(),
'height' => array(),
'src' => array(),
'width' => array(),
),
'li' => array(
'class' => array(),
),
'ol' => array(
'class' => array(),
),
'option' => array(
'value' => array(),
'selected' => array(),
),
'p' => array(
'class' => array(),
),
'q' => array(
'cite' => array(),
'title' => array(),
),
'ul' => array(
'class' => array(),
),
'select' => array(
'id' => array(),
'class' => array(),
'name' => array(),
),
'span' => array(
'class' => array(),
'title' => array(),
'style' => array(),
),
'strike' => array(),
'strong' => array(),
);
}