fonts/etc_fonts/conf.avail/90-fonts-nanum.conf

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <!-- workaround for wrong style and weight -->
  <match target="scan">
    <test name="fullname" qual="any" compare="eq">
      <string>NanumMyeongjoBold</string><string>나눔명조 Bold</string>
      <string>NanumGothicBold</string><string>나눔고딕 Bold</string>
    </test>
    <edit name="style" mode="assign">
      <string>Bold</string>
    </edit>
    <edit name="weight" mode="assign">
      <const>bold</const>
    </edit>
  </match>
  <!-- fallback of the MS fonts -->
  <alias>
    <family>Gulim</family><family>굴림</family>
    <family>Dotum</family><family>돋움</family>
    <prefer><family>NanumGothic</family></prefer>
  </alias>
  <alias>
    <family>Batang</family><family>바탕</family>
    <prefer><family>NanumMyeongjo</family></prefer>
  </alias>
  <!-- specify fallbacks for the missing glyphs. -->
  <match target="pattern">
    <test name="family" compare="eq">
      <string>나눔고딕</string><string>NanumGothic</string>
    </test>
    <edit name="family" mode="append">
      <string>UnDotum</string>
      <string>DejaVu Sans</string>
    </edit>
  </match>
  <match target="pattern">
    <test name="family" compare="eq">
      <string>나눔명조</string><string>NanumMyeongjo</string>
    </test>
    <edit name="family" mode="append">
      <string>UnBatang</string>
      <string>DejaVu Serif</string>
    </edit>
  </match>
  <!-- default sans and serif
       TODO: it will be moved to fontconfig default configs -->
  <match target="pattern">
    <test qual="any" name="lang" compare="contains">
      <string>ko</string>
    </test>
    <test qual="any" name="family" compare="eq">
      <string>sans-serif</string>
    </test>
    <edit name="family" mode="prepend_first" binding="same">
      <string>NanumGothic</string>
    </edit>
  </match>
  <match target="pattern">
    <test qual="any" name="lang" compare="contains">
      <string>ko</string>
    </test>
    <test qual="any" name="family" compare="eq">
      <string>serif</string>
    </test>
    <edit name="family" mode="prepend_first" binding="same">
      <string>NanumMyeongjo</string>
    </edit>
  </match>
</fontconfig>