diff --git a/src/iso19111/operation/parammappings.cpp b/src/iso19111/operation/parammappings.cpp
index 0c6956d1a9..2d4fc2c549 100644
--- a/src/iso19111/operation/parammappings.cpp
+++ b/src/iso19111/operation/parammappings.cpp
@@ -1038,6 +1038,12 @@ const struct MethodNameCode methodNameCodesList[] = {
     METHOD_NAME_CODE(NADCON5_3D),
     METHOD_NAME_CODE(VERTCON),
     METHOD_NAME_CODE(GEOCENTRIC_TRANSLATION_BY_GRID_INTERPOLATION_IGN),
+    METHOD_NAME_CODE(VERTICALGRID_NZLVD),
+    METHOD_NAME_CODE(VERTICALGRID_BEV_AT),
+    METHOD_NAME_CODE(VERTICALGRID_GTX),
+    METHOD_NAME_CODE(VERTICALGRID_ASC),
+    METHOD_NAME_CODE(VERTICALGRID_GTG),
+    METHOD_NAME_CODE(VERTICALGRID_PL_TXT),
     // PointMotionOperation
     METHOD_NAME_CODE(POINT_MOTION_BY_GRID_CANADA_NTV2_VEL),
 };
diff --git a/src/iso19111/operation/singleoperation.cpp b/src/iso19111/operation/singleoperation.cpp
index cfc0900935..779d922042 100644
--- a/src/iso19111/operation/singleoperation.cpp
+++ b/src/iso19111/operation/singleoperation.cpp
@@ -2159,7 +2159,6 @@ bool Transformation::isGeographic3DToGravityRelatedHeight(
         "1126", // Vertical change by geoid grid difference (NRCan)
         "1127", // Geographic3D to Depth (gtg)
         "1128", // Geog3D to Geog2D+Depth (gtg)
-        "1129", // Vertical Offset by Grid Interpolation (gtg)
         "1135", // Geog3D to Geog2D+GravityRelatedHeight (NGS bin)
         "9661", // Geographic3D to GravityRelatedHeight (EGM)
         "9662", // Geographic3D to GravityRelatedHeight (Ausgeoid98)
@@ -2312,6 +2311,7 @@ static bool isRegularVerticalGridMethod(int methodEPSGCode,
     return methodEPSGCode == EPSG_CODE_METHOD_VERTICALGRID_NZLVD ||
            methodEPSGCode == EPSG_CODE_METHOD_VERTICALGRID_BEV_AT ||
            methodEPSGCode == EPSG_CODE_METHOD_VERTICALGRID_GTX ||
+           methodEPSGCode == EPSG_CODE_METHOD_VERTICALGRID_ASC ||
            methodEPSGCode == EPSG_CODE_METHOD_VERTICALGRID_GTG ||
            methodEPSGCode == EPSG_CODE_METHOD_VERTICALGRID_PL_TXT;
 }
diff --git a/src/proj_constants.h b/src/proj_constants.h
index 0e3c71f639..dba70c8375 100644
--- a/src/proj_constants.h
+++ b/src/proj_constants.h
@@ -681,6 +681,10 @@
 #define EPSG_NAME_METHOD_VERTICALGRID_GTX                                      \
     "Vertical Offset by Grid Interpolation (gtx)"
 
+#define EPSG_CODE_METHOD_VERTICALGRID_ASC 1085
+#define EPSG_NAME_METHOD_VERTICALGRID_ASC                                      \
+    "Vertical Offset by Grid Interpolation (asc)"
+
 #define EPSG_CODE_METHOD_VERTICALGRID_GTG 1129
 #define EPSG_NAME_METHOD_VERTICALGRID_GTG                                      \
     "Vertical Offset by Grid Interpolation (gtg)"