What is default fallback font of FoxIt Reader on linux

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http://stackoverflow.com – I'm making a PDF and I don't want to embed fonts inside it. When I used Tahoma Foxit Reader substituted it for some default font on linux. What is this font? What font should I use so the Foxit Reader will not have to substitute font? Installing fonts is not an option since the Client should be able to view this PDF on linux without having to install some fonts and stuff. Can't embed whole fonts since the PDF grows from 100KB to 1000KB then, can't also embed subset of font because used component doesn't allow it. I want to know this font since I use EASTERN_EUROPEAN charset for special ch (HowTos)