Font
From Scriptwiki
/font [-asbidz|window] <fontsize> <fontname>
This allows you to change the font for the current window. If no parameters are specified, the font dialog pops up, otherwise the specified parameters are used.
Note: If you use a negative number for the font size, it will match the size of fonts in the font dialog.
-a switch applies the setting to the active window, -s to the status window. -b switch makes the font bold and the -i switch makes it italic. -d switch makes the font the default for that type of window, eg. for all channels, or all chats. -z switch clears all font settings and sets all windows to the specified font. If no font is specified, all windows are set to default font settings.