diff --git a/doc/RTD/source/SubgridModels/EAGLE/index.rst b/doc/RTD/source/SubgridModels/EAGLE/index.rst
index 4c03a7013c21898194134a2188b638beb326366c..e2489452ef6ce73d9ca98e63f660fc65e0113f38 100644
--- a/doc/RTD/source/SubgridModels/EAGLE/index.rst
+++ b/doc/RTD/source/SubgridModels/EAGLE/index.rst
@@ -143,6 +143,37 @@ Whilst one would use the following values for solar abundances
      init_abundance_Silicon:      6.825874e-4  # Mass fraction in Silicon
      init_abundance_Iron:         1.1032152e-3 # Mass fraction in Iron
 
+Individual element abundances for each particle can also be read
+directly from the ICs. By default these are overwritten in the code by
+the values read from the YAML file. However, users can set the
+parameter ``init_abundance_metal`` to ``-1`` to make SWIFT ignore the
+values provided in the parameter file:
+
+.. code:: YAML
+
+   EAGLEChemistry:
+     init_abundance_metal:       -1     # Read the particles' metal mass fractions from the ICs.
+
+
+The ICs must then contain values for these three fields (same as what
+is written to the snapshots):
+
++----------------------------------+-------------------------------------+-----------+-----------------------------+
+| Name                             | Description                         | Units     | Comments                    |
++==================================+=====================================+===========+=============================+
+| ``ElementAbundance``             | | Fraction of the gas/star mass     | [-]       | | Array of length           |
+|                                  | | in the different elements         |           | | 9 for each particle       |
++----------------------------------+-------------------------------------+-----------+-----------------------------+
+| ``Metallicity``                  | | Fraction of the gas/star mass     | [-]       |                             |
+|                                  | | in *all* metals                   |           |                             |
++----------------------------------+-------------------------------------+-----------+-----------------------------+
+| ``IronMassFracFromSNIa``         | | Fraction of the *total* gas/star  | [-]       |                             |
+|                                  | | mass in *iron* produced produced  |           |                             |
+|                                  | | by enrichment from SNIa stars     |           |                             |
++----------------------------------+-------------------------------------+-----------+-----------------------------+
+
+If these fields are absent, then a value of ``0`` will be used for all
+of them, likely leading to issues in the way the code will run.
 
 .. _EAGLE_cooling: