<fontconfig>

<match>

  <test name="lang" compare="contains">

    <string>ar</string>

  </test>

  <test name="family">

    <string>sans-serif</string>

  </test>

  <edit name="family" mode="prepend" >

    <string>KacstScreen</string>

  </edit>

</match>

<alias>

  <family>KacstScreen</family>

  <default>

    <family>sans-serif</family>

  </default>

</alias>

</fontconfig>