Option Name:zph_preserve_miss_tos_mask
Replaces:
Requires:USE_ZPH_QOS
Default Value:zph_preserve_miss_tos_mask 255
Suggested Config:

       Allows you to mask certain bits in the TOS received from the
       remote server, before copying the value to the TOS send towards
       clients.
       Default: 255 (TOS from server is not changed).