anchor.diff:  optionally filtered.
   
   ===== Query parameters
  -*filter*=string[,string ...]::
  +*filter*=[string[,string ...]]::
     (_optional_)
     When set, filter the properties returned by the names in the filter string.
   
  
positive.code: Returns properties for the device, optionally filtered.
  
  ===== Query parameters
  *filter*=string[,string ...]::
    (_optional_)
    When set, filter the properties returned by the names in the filter string.
  
  
negative.code: ==== +HTTP POST+
  
  ===== Query parameters
  *filter*=[string[,string ...]]::
    (_optional_)
    When set, filter the properties returned by the names in the filter string.
  
  