diff --git a/core/nwb.ecephys.yaml b/core/nwb.ecephys.yaml
index a63be324..be5e5a0c 100644
--- a/core/nwb.ecephys.yaml
+++ b/core/nwb.ecephys.yaml
@@ -288,17 +288,17 @@ groups:
   - name: x
     neurodata_type_inc: VectorData
     dtype: float32
-    doc: x coordinate of the channel location in the brain (+x is posterior).
+    doc: x coordinate of the channel location in the brain (+x is posterior). Units should be specified in microns.
     quantity: '?'
   - name: y
     neurodata_type_inc: VectorData
     dtype: float32
-    doc: y coordinate of the channel location in the brain (+y is inferior).
+    doc: y coordinate of the channel location in the brain (+y is inferior). Units should be specified in microns.
     quantity: '?'
   - name: z
     neurodata_type_inc: VectorData
     dtype: float32
-    doc: z coordinate of the channel location in the brain (+z is right).
+    doc: z coordinate of the channel location in the brain (+z is right). Units should be specified in microns.
     quantity: '?'
   - name: imp
     neurodata_type_inc: VectorData
@@ -313,17 +313,17 @@ groups:
   - name: rel_x
     neurodata_type_inc: VectorData
     dtype: float32
-    doc: x coordinate in electrode group
+    doc: x coordinate in electrode group. Units should be specified in microns.
     quantity: '?'
   - name: rel_y
     neurodata_type_inc: VectorData
     dtype: float32
-    doc: y coordinate in electrode group
+    doc: y coordinate in electrode group. Units should be specified in microns.
     quantity: '?'
   - name: rel_z
     neurodata_type_inc: VectorData
     dtype: float32
-    doc: z coordinate in electrode group
+    doc: z coordinate in electrode group. Units should be specified in microns.
     quantity: '?'
   - name: reference
     neurodata_type_inc: VectorData
diff --git a/docs/format/source/format_release_notes.rst b/docs/format/source/format_release_notes.rst
index 237afe2c..88088fa5 100644
--- a/docs/format/source/format_release_notes.rst
+++ b/docs/format/source/format_release_notes.rst
@@ -32,6 +32,8 @@ Minor changes
 - Made ``EventDetection.times`` optional and deprecated. Use `source_idx` instead. (#620)
 - Clarified documentation of ``PlaneSegmentation`` that at least one of ``image_mask``, ``pixel_mask``,
   and ``voxel_mask`` is required. (#636)
+- Specified that units for ``ElectrodesTable`` coordinate fields (``x``, ``y``, ``z``, ``rel_x``, ``rel_y``, ``rel_z``)
+  should be in microns. (#658)
 
 2.8.0 (November 24, 2024)
 -------------------------