DSCP Codepoint on HTTPS over DNS package

Hi there!,
today i looked some other package and i seen https-dns-proxy here.. I know how it work and what can it do but there a option named "DSCP Codepoint" that is unknown for me. I've done some search but i don't understood what format must be used. Someone help me to understand? Some list available with description about code? Thank guys!

Up . Nobody has used DSCP?