diff --git a/doc/source/generating_joint_analysis.rst b/doc/source/generating_joint_analysis.rst
index 88b4c1d8d3259f01b76f07e5c27d85db7c62fffe..d6b38869af551286df81ed17f0c16eade101e2ff 100644
--- a/doc/source/generating_joint_analysis.rst
+++ b/doc/source/generating_joint_analysis.rst
@@ -37,6 +37,22 @@ By default, all the traits will have the same weight.
 
 If the user wishes to, she/he can specify a vector of weight by using the --custom-loadings option.
 
+.. code-block:: shell
+
+  jass create-project-data --init-table-path inittable_Update_COVID19.hdf5 --phenotypes z_INFECTION_INFLUENZA z_INFECTION_EAR-INFECTIONS --worktable-path worktable_test_SumZ.hdf5 --manhattan-plot-path manhattan_SumZ_test.png --quadrant-plot-path quadrant_SumZ_test.png --qq-plot-path QQplots_SumZ_test.png --sumz --custom-loadings test_loadings.csv"
+
+the test_loadings.csv is comma separated file with the following structure:
+
++-----------------------------+-------+
+| trait                       | weight| 
++=============================+=======+
+| z_INFECTION_INFLUENZA       |   0.8 |
++-----------------------------+-------+
+| z_INFECTION_EAR-INFECTIONS  | -0.2  |
++-----------------------------+-------+
+
+
+
 Access HDFStore components
 --------------------------