--- a/OrthancServer/Sources/OrthancRestApi/OrthancRestResources.cpp	Tue Apr 04 07:09:22 2023 +0200
+++ b/OrthancServer/Sources/OrthancRestApi/OrthancRestResources.cpp	Tue Apr 04 09:16:12 2023 +0200
@@ -3072,6 +3072,8 @@
     static const char* const KEY_QUERY = "Query";
     static const char* const KEY_REQUESTED_TAGS = "RequestedTags";
     static const char* const KEY_SINCE = "Since";
+    static const char* const KEY_WITH_LABELS = "WithLabels";        // New in Orthanc 1.12.0
+    static const char* const KEY_WITHOUT_LABELS = "WithoutLabels";  // New in Orthanc 1.12.0
 
     if (call.IsDocumentation())
     {
@@ -3101,6 +3103,10 @@
                          "all Main Dicom Tags to keep backward compatibility with Orthanc prior to 1.11.0.", false)
         .SetRequestField(KEY_QUERY, RestApiCallDocumentation::Type_JsonObject,
                          "Associative array containing the filter on the values of the DICOM tags", true)
+        .SetRequestField(KEY_WITH_LABELS, RestApiCallDocumentation::Type_JsonListOfStrings,
+                         "List of strings specifying which labels must be present in the resources (new in Orthanc 1.12.0)", true)
+        .SetRequestField(KEY_WITHOUT_LABELS, RestApiCallDocumentation::Type_JsonListOfStrings,
+                         "List of strings specifying which labels must not be present in the resources (new in Orthanc 1.12.0)", true)
         .AddAnswerType(MimeType_Json, "JSON array containing either the Orthanc identifiers, or detailed information "
                        "about the reported resources (if `Expand` argument is `true`)");
       return;
@@ -3131,25 +3137,37 @@
              request[KEY_CASE_SENSITIVE].type() != Json::booleanValue)
     {
       throw OrthancException(ErrorCode_BadRequest, 
-                             "Field \"" + std::string(KEY_CASE_SENSITIVE) + "\" should be a Boolean");
+                             "Field \"" + std::string(KEY_CASE_SENSITIVE) + "\" must be a Boolean");
     }
     else if (request.isMember(KEY_LIMIT) && 
              request[KEY_LIMIT].type() != Json::intValue)
     {
       throw OrthancException(ErrorCode_BadRequest, 
-                             "Field \"" + std::string(KEY_LIMIT) + "\" should be an integer");
+                             "Field \"" + std::string(KEY_LIMIT) + "\" must be an integer");
     }
     else if (request.isMember(KEY_SINCE) &&
              request[KEY_SINCE].type() != Json::intValue)
     {
       throw OrthancException(ErrorCode_BadRequest, 
-                             "Field \"" + std::string(KEY_SINCE) + "\" should be an integer");
+                             "Field \"" + std::string(KEY_SINCE) + "\" must be an integer");
     }
     else if (request.isMember(KEY_REQUESTED_TAGS) &&
              request[KEY_REQUESTED_TAGS].type() != Json::arrayValue)
     {
       throw OrthancException(ErrorCode_BadRequest, 
-                             "Field \"" + std::string(KEY_REQUESTED_TAGS) + "\" should be an array");
+                             "Field \"" + std::string(KEY_REQUESTED_TAGS) + "\" must be an array");
+    }
+    else if (request.isMember(KEY_WITH_LABELS) &&
+             request[KEY_WITH_LABELS].type() != Json::arrayValue)
+    {
+      throw OrthancException(ErrorCode_BadRequest, 
+                             "Field \"" + std::string(KEY_WITH_LABELS) + "\" must be an array of strings");
+    }
+    else if (request.isMember(KEY_WITHOUT_LABELS) &&
+             request[KEY_WITHOUT_LABELS].type() != Json::arrayValue)
+    {
+      throw OrthancException(ErrorCode_BadRequest, 
+                             "Field \"" + std::string(KEY_WITHOUT_LABELS) + "\" must be an array of strings");
     }
     else
     {
@@ -3172,7 +3190,7 @@
         if (tmp < 0)
         {
           throw OrthancException(ErrorCode_ParameterOutOfRange,
-                                 "Field \"" + std::string(KEY_LIMIT) + "\" should be a positive integer");
+                                 "Field \"" + std::string(KEY_LIMIT) + "\" must be a positive integer");
         }
 
         limit = static_cast<size_t>(tmp);
@@ -3185,7 +3203,7 @@
         if (tmp < 0)
         {
           throw OrthancException(ErrorCode_ParameterOutOfRange,
-                                 "Field \"" + std::string(KEY_SINCE) + "\" should be a positive integer");
+                                 "Field \"" + std::string(KEY_SINCE) + "\" must be a positive integer");
         }
 
         since = static_cast<size_t>(tmp);
@@ -3208,7 +3226,7 @@
         if (request[KEY_QUERY][members[i]].type() != Json::stringValue)
         {
           throw OrthancException(ErrorCode_BadRequest,
-                                 "Tag \"" + members[i] + "\" should be associated with a string");
+                                 "Tag \"" + members[i] + "\" must be associated with a string");
         }
 
         const std::string value = request[KEY_QUERY][members[i]].asString();
@@ -3223,6 +3241,36 @@
         }
       }
 
+      if (request.isMember(KEY_WITH_LABELS))  // New in Orthanc 1.12.0
+      {
+        for (Json::Value::ArrayIndex i = 0; i < request[KEY_WITH_LABELS].size(); i++)
+        {
+          if (request[KEY_WITH_LABELS][i].type() != Json::stringValue)
+          {
+            throw OrthancException(ErrorCode_BadRequest, "Field \""+ std::string(KEY_WITH_LABELS) + "\" must contain strings");
+          }
+          else
+          {
+            query.AddWithLabel(request[KEY_WITH_LABELS][i].asString());
+          }
+        }
+      }
+      
+      if (request.isMember(KEY_WITHOUT_LABELS))  // New in Orthanc 1.12.0
+      {
+        for (Json::Value::ArrayIndex i = 0; i < request[KEY_WITHOUT_LABELS].size(); i++)
+        {
+          if (request[KEY_WITHOUT_LABELS][i].type() != Json::stringValue)
+          {
+            throw OrthancException(ErrorCode_BadRequest, "Field \""+ std::string(KEY_WITHOUT_LABELS) + "\" must contain strings");
+          }
+          else
+          {
+            query.AddWithoutLabel(request[KEY_WITHOUT_LABELS][i].asString());
+          }
+        }
+      }
+      
       FindVisitor visitor(OrthancRestApi::GetDicomFormat(request, DicomToJsonFormat_Human), context.GetFindStorageAccessMode());
       context.Apply(visitor, query, level, since, limit);
       visitor.Answer(call.GetOutput(), context, level, expand, requestedTags);