OmidMnz

I was looking for a similar comment. Plasma does exactly that too. These are probably provided from this line in its .desktop file:

Keywords=Slideshow;Slides;OpenDocument Presentation;Microsoft PowerPoint;Microsoft Works;OpenOffice Impress;odp;ppt;pptx;

https://addons.mozilla.org/en-US/firefox/addon/youtube-recommended-videos/ Unhook "ignore"s them for me! It is available for other browsers too.