Comment 1 for bug 1774755

I wanted to add this link as well -- it's the freedesktop icon naming spec page which lists many of the generic icon names.

https://specifications.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html#mimetypes

Also just for reference to maybe help others out, I am adding here all the icon names that I have found so far that Catfish uses/prefers. I know it's not a complete list but these are common ones anyway.

I've found that for many files it won't use an icon specific to that file or even that type of file. For example a gz file, part file, mts file, and lzma file will all use the text file icon. Many fall back to gtk-file icon so a json, exe, xcf, ttf, otf, and many others use the same icon.

gnome-mime-application-javascript.svg
gnome-mime-application-msword.svg
gnome-mime-application-pdf.svg
gnome-mime-application-postscript.svg
gnome-mime-application-rar.svg
gnome-mime-application-vnd.ms-excel.svg
gnome-mime-application-vnd.ms-powerpoint.svg
gnome-mime-application-vnd.oasis.opendocument.spreadsheet.svg
gnome-mime-application-vnd.oasis.opendocument.text.svg
gnome-mime-application-vnd.openxmlformats-officedocument.spreadsheetml.sheet.svg
gnome-mime-application-vnd.openxmlformats-officedocument.wordprocessingml.document.svg
gnome-mime-application-x-7z-compressed.svg
gnome-mime-application-x-abiword.svg
gnome-mime-application-x-gnumeric.svg
gnome-mime-application-xml.svg
gnome-mime-application-x-shockwave-flash.svg
gnome-mime-application-x-tar.svg
gnome-mime-application-zip.svg
gnome-mime-audio.svg
gnome-mime-image-bmp.svg
gnome-mime-image-gif.svg
gnome-mime-image-jpeg.svg
gnome-mime-image-png.svg
gnome-mime-image.svg
gnome-mime-image-svg.svg
gnome-mime-image-tiff.svg
gnome-mime-text-css.svg
gnome-mime-text-html.svg
gnome-mime-text-plain.svg
gnome-mime-text-x-java.svg
gnome-mime-text-x-python.svg
gnome-mime-text-x-sh.svg
gnome-mime-video.svg
gnome-mime-video-x-ms-wmv.svg
gtk-directory.svg
gtk-file.svg