code: function MsPowerpoint_Clean(&$Txt) {
  		$this->MsPowerpoint_CleanRpr($Txt, 'a:rPr');
  		$Txt = str_replace('<a:rPr/>', '', $Txt);
  
  		$this->MsPowerpoint_CleanRpr($Txt, 'a:endParaRPr');
  		$Txt = str_replace('<a:endParaRPr/>', '', $Txt); // do not delete, can change layout
  
  		// join split elements
  		$Txt = str_replace('</a:t><a:t>', '', $Txt);
  		$Txt = str_replace('</a:t></a:r><a:r><a:t>', '', $Txt); // this join TBS split tags
  
  		// delete empty elements
  		$Txt = str_replace('<a:t></a:t>', '', $Txt);
  		$Txt = str_replace('<a:r></a:r>', '', $Txt);
  	}
docs: Clean tags in an Ms Powerpoint slide