diff --git a/changelog.md b/changelog.md
index c0f65be..fde1254 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,6 +1,9 @@
 # Changelog
 
-## 17th Jan 2023 (V0.7)
+## 6th December 2023 (V0.8)
+- Add SpectralWidth as a standard defined header value. However the dwell time stored in `pixdim[4]` is defined as the preferentially used value.
+
+## 17th January 2023 (V0.7)
 - Update anonymisation flags for ManufacturersModelName and DeviceSerialNumber as per US HIPPA guidance.
 
 ## 23rd July 2022 (V0.6)
diff --git a/specification.MD b/specification.MD
index 3fc5cae..c6d63df 100644
--- a/specification.MD
+++ b/specification.MD
@@ -1,6 +1,6 @@
 # NIfTI MRS format specification
 
-Version 0.7
+Version 0.8
 
 
 # 1 Purpose
@@ -429,6 +429,13 @@ This appendix contains the standard-defined metadata keys. Keys have been groupe
    <td><strong>Description</strong></td>
    <td><strong>Anon (Y/N)</strong></td>
   </tr>
+  <tr>
+   <td>SpectralWidth</td>
+   <td>number</td>
+   <td>Hz</td>
+   <td>The spectral bandwidth of the MR signal that is sampled. Inverse of the dwell time. NIfTI-MRS standard compliant software will always preferentially infer the spectral width from the dwell time stored in the NIfTI pixdim field. Units: hertz</td>
+   <td>N</td>
+  </tr>
   <tr>
    <td>EchoTime</td>
    <td>number</td>