[ownedbycats]

I have this to display icons for formats, and an unknown icon if none are present:

program: 

formats = approximate_formats();

   strcat
   (
		if "azw3" inlist formats then 'formats_azw3.png:' fi,
		if "cbz" inlist formats then 'formats_cbz.png:' fi,	
		if "epub" inlist formats then 'formats_epub.png:' fi,
		if "html" inlist formats then 'formats_html.png:' fi,
		if "mobi" inlist formats then 'formats_mobi.png:' fi,
		if "paperbook" inlist formats then 'formats_paperbook.png:' fi,
		if "pdf" inlist formats then 'formats_pdf.png:' fi,	
		if "txt" inlist formats then 'formats_txt.png:' fi,	
		if "(overdrive|paperloan)" inlist formats then 'formats_overdrive.png:' fi,	

		if list_difference(formats, 'azw3, cbz, epub, html, mobi, paperbook, pdf, txt, overdrive, paperloan', ',') then 'formats_unknown.png' fi	
   )

Very repetitive. Except for paperloan, Is there a way to regex this to a single line, and would be any faster?