deny-class

Would it be possible to have a new keyword - maybe called "deny-class" for with IP address allocation based on client classification. Something like the following:

"pools": [   
   {   
      "client-class": "SPECIAL_CLIENTS",   
      "option-data": [],   
      "pool": "10.0.0.50-10.0.0.100"   
   },
   {
      "deny-class": "UNWELCOME_CLIENTS",   
      "option-data": [],   
      "pool": "10.0.0.101-10.50.0.255"   
   }   
]

RT #18741