diff --git a/siibra/atlases/parcellationmap/v0.1.json b/siibra/atlases/parcellationmap/v0.1.json
index 1426aab..6310750 100644
--- a/siibra/atlases/parcellationmap/v0.1.json
+++ b/siibra/atlases/parcellationmap/v0.1.json
@@ -29,13 +29,17 @@
             "items": {
                 "$ref": "urn:siibra-local:siibra/attr/v0.1.json"
             }
+        },
+        "region_mapping": {
+            "$ref": "urn:siibra-local:siibra/attr/util/region_mapping/v0.1.json"
         }
     },
     "required": [
         "@type",
         "maptype",
         "parcellation_id",
-        "space_id"
+        "space_id",
+        "region_mapping"
     ],
     "additionalProperties": false
 }
\ No newline at end of file
diff --git a/siibra/attr/data/_volume_base/v0.1.json b/siibra/attr/data/_volume_base/v0.1.json
index f8655aa..acc87d3 100644
--- a/siibra/attr/data/_volume_base/v0.1.json
+++ b/siibra/attr/data/_volume_base/v0.1.json
@@ -10,14 +10,6 @@
         },
         "colormap": {
             "$ref": "#/definitions/colormap"
-        },
-        "mapping": {
-            "type": "object",
-            "patternProperties": {
-                ".+": {
-                    "$ref": "#/definitions/mappingValue"
-                }
-            }
         }
     },
     "required": [
@@ -30,24 +22,6 @@
                     "const": "magma"
                 }
             ]
-        },
-        "mappingValue": {
-            "type": "object",
-            "properties": {
-                "range": {
-                    "type": "array",
-                    "items": {
-                        "type": "number"
-                    }
-                },
-                "color": {
-                    "type": "string"
-                },
-                "label": {
-                    "type": "number"
-                }
-            },
-            "additionalProperties": false
         }
     }
 }
diff --git a/siibra/attr/desc/attribute_mapping/v0.1.json b/siibra/attr/desc/attribute_mapping/v0.1.json
new file mode 100644
index 0000000..520dd1c
--- /dev/null
+++ b/siibra/attr/desc/attribute_mapping/v0.1.json
@@ -0,0 +1,133 @@
+{
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "type": "object",
+    "oneOf": [
+        {
+            "type": "object",
+            "properties": {
+                "parcellation_id": {
+                    "type": "string"
+                },
+                "region_mapping": {
+                    "$ref": "urn:siibra-local:siibra/attr/util/region_mapping/v0.1.json"
+                }
+            },
+            "required": ["parcellation_id", "region_mapping"],
+            "additionalProperties": false
+        },
+        {
+            "type": "object",
+            "properties": {
+                "ref_type": {
+                    "$ref": "#/definitions/ebrainsref_type"
+                },
+                "refs": {
+                    "$ref": "#/definitions/ebrainsref_mapping"
+                }
+            }
+        }
+    ],
+    "properties": {
+        "@type": {
+            "const": "siibra/attr/desc/attribute_mapping/v0.1"
+        }
+    },
+    "required": [
+        "@type"
+    ],
+    "examples": [
+        {
+            "@type": "siibra/attr/desc/attribute_mapping/v0.1",
+            "parcellation_id": "minds/core/parcellationatlas/v1.0.0/94c1125b-b87e-45e4-901c-00daee7f2579-300",
+            "region_mappings": {
+                "Area 45 (IFG) - left hemisphere": [
+                    {
+                        "@type": "volume/ref",
+                        "label": 1,
+                        "target": "Left hemisphere volume of Julich Brain 3.0.3 in ICBM 152 space",
+                        "color": "#A76792"
+                    }
+                ],
+                "Area 45 (IFG) - right hemisphere": [
+                    {
+                        "@type": "volume/ref",
+                        "label": 1,
+                        "target": "Right hemisphere volume of Julich Brain 3.0.3 in ICBM 152 space",
+                        "color": "#A76792"
+                    }
+                ]
+            }
+        },
+        {
+            "@type": "siibra/attr/desc/attribute_mapping/v0.1",
+            "parcellation_id": "minds/core/parcellationatlas/v1.0.0/94c1125b-b87e-45e4-901c-00daee7f2579-300",
+            "region_mappings": {
+                "Area 45 (IFG) - left hemisphere": [
+                    {
+                        "@type": "csv/row-index",
+                        "index": 0
+                    }
+                ],
+                "Area 44 (IFG) - left hemisphere": [
+                    {
+                        "@type": "csv/row-index",
+                        "index": 1
+                    }
+                ]
+            }
+        },
+        {
+            "@type": "siibra/attr/desc/attribute_mapping/v0.1",
+            "ref_type": "openminds/DatasetVersion",
+            "refs": {
+                "cb40a501-b155-4c2f-8df3-0ee7c5f1ed00": [
+                    {
+                        "target": "Detailed map of VTM (Amygdala) - left hemisphere in Julich Brain in Big Brain"
+                    },
+                    {
+                        "target": "Detailed map of VTM (Amygdala) - right hemisphere in Julich Brain in Big Brain"
+                    }
+                ]
+            }
+        }
+    ],
+    "definitions": {
+        "ebrainsref_type": {
+            "oneOf": [
+                {
+                    "const": "openminds/DatasetVersion"
+                },
+                {
+                    "const": "openminds/Dataset"
+                },
+                {
+                    "const": "openminds/AtlasAnnotation"
+                },
+                {
+                    "const": "minds/core/dataset/v1.0.0"
+                }
+            ]
+        },
+        "ebrainsref_mapping": {
+            "type": "object",
+            "properties": {
+                "refs": {
+                    "type": "object",
+                    "patternProperties": {
+                        "^[0-9a-f-]+$": {
+                            "type": "array",
+                            "items": {
+                                "type": "object",
+                                "properties": {
+                                    "target": {
+                                        "type": "string"
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/siibra/attr/desc/v0.1.json b/siibra/attr/desc/v0.1.json
index 7c20c95..9ba3a72 100644
--- a/siibra/attr/desc/v0.1.json
+++ b/siibra/attr/desc/v0.1.json
@@ -39,6 +39,9 @@
         },
         {
             "$ref": "urn:siibra-local:siibra/attr/desc/categorization/v0.1.json"
+        },
+        {
+            "$ref": "urn:siibra-local:siibra/attr/desc/attribute_mapping/v0.1.json"
         }
     ]
 }
diff --git a/siibra/attr/util/region_mapping/v0.1.json b/siibra/attr/util/region_mapping/v0.1.json
new file mode 100644
index 0000000..47142c9
--- /dev/null
+++ b/siibra/attr/util/region_mapping/v0.1.json
@@ -0,0 +1,143 @@
+{
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "type": "object",
+    "patternProperties": {
+        "^.*$": {
+            "type": "array",
+            "items": {
+                "$ref": "#/definitions/region-mapping-target"
+            }
+        }
+    },
+    "description": "Describes how a subset of regions in a parcellation scheme connects to other attributes. At the moment, labelled volume mapping, statistical volume linking, and csv/row-index can be described. \n\nPlease note that this schema is not meant to be standalone, as the parcellation_id is deliberately not included. The parent node should contain parcellation_id.",
+    "examples": [
+        {
+            "Area 45 (IFG) - left hemisphere": [
+                {
+                    "@type": "volume/ref",
+                    "label": 1,
+                    "target": "Left hemisphere volume of Julich Brain 3.0.3 in ICBM 152 space",
+                    "color": "#A76792"
+                }
+            ]
+        },
+        {
+            "Area 45 (IFG) - left hemisphere": [
+                {
+                    "@type": "volume/ref",
+                    "range": [0, 0.98],
+                    "target": "Statistical map of Area 45 (IFG) - left hemisphere in ICBM 152 space"
+                }
+            ]
+        },
+        {
+            "Component 3: Calcarine cortex posterior": [
+                {
+                    "@type": "volume/ref",
+                    "subspace":  [
+                        ":",
+                        ":",
+                        ":",
+                        2
+                    ],
+                    "range": [],
+                    "target": "DiFuMo Atlas (64 dimensions) on MNI 152 ICBM 2009c Nonlinear Asymmetric - statistical - 32 regions"
+                }
+            ]
+        },
+        {
+            "Area 45 (IFG) - left hemisphere": [
+                {
+                    "@type": "csv/row-index",
+                    "index": 0
+                }
+            ]
+        }
+    ],
+    "definitions": {
+        "target_protocol": {
+            "type": "object",
+            "properties": {
+                "target": {
+                    "type": "string"
+                }
+            }
+        },
+        "region-mapping-target": {
+            "type": "object",
+            "allOf": [
+                {
+                    "$ref": "#/definitions/target_protocol"
+                }
+            ],
+            "oneOf": [
+                {
+                    "$ref": "#/definitions/volume"
+                },
+                {
+                    "$ref": "#/definitions/row-index"
+                }
+            ]
+        },
+        "volume": {
+            "type": "object",
+            "oneOf": [
+                {
+                    "type": "object",
+                    "properties": {
+                        "label": {
+                            "type": "number"
+                        },
+                        "color": {
+                            "type": "string",
+                            "pattern": "#[a-fA-F0-9]{6}"
+                        }
+                    },
+                    "required": ["label"]
+                },
+                {
+                    "type": "object",
+                    "properties": {
+                        "range": {
+                            "type": "array",
+                            "items": {
+                                "type": "number"
+                            }
+                        },
+                        "subspace": {
+                            "type": "array",
+                            "items": {
+                                "anyOf": [
+                                    {
+                                        "const": ":"
+                                    },
+                                    {
+                                        "type": "number"
+                                    }
+                                ]
+                            }
+                        }
+                    },
+                    "required": ["range"]
+                }
+            ],
+            "properties": {
+                "@type": {
+                    "const": "volume/ref"
+                }
+            },
+            "required": ["@type"]
+        },
+        "row-index": {
+            "type": "object",
+            "properties": {
+                "@type": {
+                    "const": "csv/row-index"
+                },
+                "index": {
+                    "type": "number"
+                }
+            }
+        }
+    }
+}
\ No newline at end of file