diff --git a/source/snapshots/snapshot_dirs.rst b/source/snapshots/snapshot_dirs.rst
index 7c9d8de..f550e43 100644
--- a/source/snapshots/snapshot_dirs.rst
+++ b/source/snapshots/snapshot_dirs.rst
@@ -95,3 +95,13 @@ for the snapshot you're interested in. See
 If you use the hdfstream module to read from a virtual snapshot, the
 server automatically reads the underlying datasets in the real
 snapshot files.
+
+.. _warning_buggy_datasets:
+
+.. warning:: Since the simulation was run, 
+   :ref:`the values of the Xray properties (now stored in the xray chunk files)<issues_xray_uvb>`
+   and :ref:`the values of the FOF IDs (now stored in the membership chunk files)<issues_rerun_fof>`
+   have been updated. Loading the virtual file will give access to the correct datasets
+   , but the original datasets are still present
+   in the SWIFT output chunk files. These original datasets should not be used.
+
diff --git a/source/support/image_pages/rerun_fof.rst b/source/support/image_pages/rerun_fof.rst
new file mode 100644
index 0000000..6c6d48b
--- /dev/null
+++ b/source/support/image_pages/rerun_fof.rst
@@ -0,0 +1,14 @@
+:orphan:
+
+Rerunning of Friend of Friends
+==============================
+
+.. _issues_rerun_fof:
+
+
+Initially, the Friends of Friends (FoF) algorithm was configured to link all particle species (dark matter and baryons) using a universal linking length.
+However, prior to generating the HBT catalogues, the FoF was rerun using dark matter (DM) particles only.
+Baryonic particles are attached to FoF groups based on their nearest DM neighbour.
+This change results in negligible changes to halo mass and membership.
+
+The final FoF group memberships are stored within the membership chunk files.
diff --git a/source/support/support_issues.rst b/source/support/support_issues.rst
index 71624b8..a15f146 100644
--- a/source/support/support_issues.rst
+++ b/source/support/support_issues.rst
@@ -222,7 +222,6 @@ Affected maps:
 Incorrect UVB used for computing X-ray values
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-
 The X-ray tables used to compute X-ray luminosities when running the simulations assumed the z=0 UV background for all redshifts. The X-ray values have been recomputed for
 all the snapshots using a corrected table. We have also recomputed the X-ray maps where possible, but the shells above :math:`z=0.5` for the
 :math:`1 \mathrm{Gpc}` runs have not been corrected.