--- a/OrthancServer/ServerContext.cpp	Mon Feb 17 17:54:40 2020 +0100
+++ b/OrthancServer/ServerContext.cpp	Thu Feb 20 20:36:47 2020 +0100
@@ -254,6 +254,11 @@
       jobsEngine_.SetWorkersCount(lock.GetConfiguration().GetUnsignedIntegerParameter("ConcurrentJobs", 2));
       saveJobs_ = lock.GetConfiguration().GetBooleanParameter("SaveJobs", true);
       metricsRegistry_->SetEnabled(lock.GetConfiguration().GetBooleanParameter("MetricsEnabled", true));
+
+      // New configuration options in Orthanc 1.5.1
+      findStorageAccessMode_ = StringToFindStorageAccessMode(lock.GetConfiguration().GetStringParameter("StorageAccessOnFind", "Always"));
+      limitFindInstances_ = lock.GetConfiguration().GetUnsignedIntegerParameter("LimitFindInstances", 0);
+      limitFindResults_ = lock.GetConfiguration().GetUnsignedIntegerParameter("LimitFindResults", 0);
     }
 
     jobsEngine_.SetThreadSleep(unitTesting ? 20 : 200);
@@ -796,44 +801,9 @@
                             size_t since,
                             size_t limit)
   {
-    LookupMode mode;
-    unsigned int databaseLimit;
+    unsigned int databaseLimit = (queryLevel == ResourceType_Instance ?
+                                  limitFindInstances_ : limitFindResults_);
       
-    {
-      // New configuration option in 1.5.1
-      OrthancConfiguration::ReaderLock lock;
-
-      std::string value = lock.GetConfiguration().GetStringParameter("StorageAccessOnFind", "Always");
-
-      if (value == "Always")
-      {
-        mode = LookupMode_DiskOnLookupAndAnswer;
-      }
-      else if (value == "Never")
-      {
-        mode = LookupMode_DatabaseOnly;
-      }
-      else if (value == "Answers")
-      {
-        mode = LookupMode_DiskOnAnswer;
-      }
-      else
-      {
-        throw OrthancException(ErrorCode_ParameterOutOfRange,
-                               "Configuration option \"StorageAccessOnFind\" "
-                               "should be \"Always\", \"Never\" or \"Answers\": " + value);
-      }
-
-      if (queryLevel == ResourceType_Instance)
-      {
-        databaseLimit = lock.GetConfiguration().GetUnsignedIntegerParameter("LimitFindInstances", 0);
-      }
-      else
-      {
-        databaseLimit = lock.GetConfiguration().GetUnsignedIntegerParameter("LimitFindResults", 0);
-      }
-    }      
-
     std::vector<std::string> resources, instances;
 
     {
@@ -846,6 +816,11 @@
 
     LOG(INFO) << "Number of candidate resources after fast DB filtering on main DICOM tags: " << resources.size();
 
+    /**
+     * "resources" contains the Orthanc ID of the resource at level
+     * "queryLevel", "instances" contains one the Orthanc ID of one
+     * sample instance from this resource.
+     **/
     assert(resources.size() == instances.size());
 
     size_t countResults = 0;
@@ -863,19 +838,54 @@
       bool hasOnlyMainDicomTags;
       DicomMap dicom;
       
-      if (mode == LookupMode_DatabaseOnly ||
-          mode == LookupMode_DiskOnAnswer ||
+      if (findStorageAccessMode_ == FindStorageAccessMode_DatabaseOnly ||
+          findStorageAccessMode_ == FindStorageAccessMode_DiskOnAnswer ||
           lookup.HasOnlyMainDicomTags())
       {
         // Case (1): The main DICOM tags, as stored in the database,
         // are sufficient to look for match
 
-        if (!GetIndex().GetAllMainDicomTags(dicom, instances[i]))
+        DicomMap tmp;
+        if (!GetIndex().GetAllMainDicomTags(tmp, instances[i]))
         {
           // The instance has been removed during the execution of the
           // lookup, ignore it
           continue;
         }
+
+#if 1
+        // New in Orthanc 1.6.0: Only keep the main DICOM tags at the
+        // level of interest for the query
+        switch (queryLevel)
+        {
+          // WARNING: Don't reorder cases below, and don't add "break"
+          case ResourceType_Instance:
+            dicom.MergeMainDicomTags(tmp, ResourceType_Instance);
+
+          case ResourceType_Series:
+            dicom.MergeMainDicomTags(tmp, ResourceType_Series);
+
+          case ResourceType_Study:
+            dicom.MergeMainDicomTags(tmp, ResourceType_Study);
+            
+          case ResourceType_Patient:
+            dicom.MergeMainDicomTags(tmp, ResourceType_Patient);
+            break;
+
+          default:
+            throw OrthancException(ErrorCode_InternalError);
+        }
+
+        // Special case of the "Modality" at the study level, in order
+        // to deal with C-FIND on "ModalitiesInStudy" (0008,0061).
+        // Check out integration test "test_rest_modalities_in_study".
+        if (queryLevel == ResourceType_Study)
+        {
+          dicom.CopyTagIfExists(tmp, DICOM_TAG_MODALITY);
+        }
+#else
+        dicom.Assign(tmp);  // This emulates Orthanc <= 1.5.8
+#endif
         
         hasOnlyMainDicomTags = true;
       }
@@ -907,8 +917,8 @@
         }
         else
         {
-          if ((mode == LookupMode_DiskOnLookupAndAnswer ||
-               mode == LookupMode_DiskOnAnswer) &&
+          if ((findStorageAccessMode_ == FindStorageAccessMode_DiskOnLookupAndAnswer ||
+               findStorageAccessMode_ == FindStorageAccessMode_DiskOnAnswer) &&
               dicomAsJson.get() == NULL &&
               isDicomAsJsonNeeded)
           {