corrected typo in docs/irf/bkg.rst
@@ -10,7 +10,7 @@ of detector coordinates and true energy.
Its format specifications are available in :ref:`gadf:bkg_3d`.
-This is the format in which IACT DL3 energy dispersions are usually provided, as an example:
+This is the format in which IACT DL3 background rates are usually provided, as an example:
.. plot:: irf/plot_bkg_3d.py
:include-source:
