o Nmap now saves the target name (if any) specified on the command

line, since this can differ from the reverse DNS results.  It can be
  particularly important when doing HTTP tests against virtual hosts.
  The data can be accessed from target->HostName() from Nmap proper
  and host.targetname from NSE scripts.  The NSE HTTP library now uses
  this for the Host header.  Thanks to Sven Klemm for adding this
  useful feature.

TargetGroup.h

@@ -134,6 +134,8 @@ class TargetGroup {
   char get_targets_type() {return targets_type;};
   /* get the netmask */
   int get_mask() {return netmask;};
+  /* is the current expression a named host */
+  int get_namedhost() {return namedhost;};
   /* Skip an octet in the range array */
   int skip_range(_octet_nums octet);
  private:
@@ -160,6 +162,8 @@ class TargetGroup {
 		  the fields are not valid */
   unsigned long ipsleft; 
 
+  // is the current target expression a named host
+  int namedhost;
 };
 
 class HostGroupState {