add_filter('tiny_mce_before_init', 'customize_tinymce');
function customize_tinymce($in) {
$in['paste_preprocess'] = "function(pl,o){
// remove the following tags completely:
o.content = o.content.replace(/<\/*(applet|area|article|aside|audio|base|basefont|bdi|bdo|body|button|canvas|command|datalist|details|embed|figcaption|figure|font|footer|frame|frameset|head|header|hgroup|hr|html|iframe|img|keygen|link|map|mark|menu|meta|meter|nav|noframes|noscript|object|optgroup|output|param|progress|rp|rt|ruby|script|section|source|span|style|summary|time|title|track|video|wbr)[^>]*>/gi,'');
// remove all attributes from these tags:
o.content = o.content.replace(/<(div|table|tbody|tr|td|th|p|b|font|strong|i|em|h1|h2|h3|h4|h5|h6|hr|ul|li|ol|code|blockquote|address|dir|dt|dd|dl|big|cite|del|dfn|ins|kbd|q|samp|small|s|strike|sub|sup|tt|u|var|caption) [^>]*>/gi,'<$1>');
// keep only href in the a tag (needs to be refined to also keep _target and ID):
// o.content = o.content.replace(/]*href=(\"|')(.*?)(\"|')[^>]*>/gi,'');
// replace br tag with p tag:
if (o.content.match(//gi)) {
o.content = o.content.replace(//gi,'
