diff --git a/doc/doxygen/modules.txt b/doc/doxygen/modules.txt
index c63fa63ad051afbf92fbc2266686a799d9f0fb14..d587f0732ce0df7277754cc7da3d86c584d6d1de 100644
--- a/doc/doxygen/modules.txt
+++ b/doc/doxygen/modules.txt
@@ -305,6 +305,11 @@
      * \defgroup FEMDiscretization Finite element method
      * \brief The finite element method
      */
+    /*!
+     * \ingroup Discretization
+     * \defgroup PoreNetworkDiscretization Pore network model discretization
+     * \brief The pore-network model discretization.
+     */
 /* ***************** Flux ******************/
 /*!
  * \defgroup Flux Flux
@@ -330,6 +335,11 @@
          * \defgroup CCMpfaFlux Flux related to the cell-centered multi-point flux approximation schemes
          * \brief Flux related to the cell-centered multi-point flux approximation schemes
          */
+    /*!
+     * \ingroup Flux
+     * \defgroup PoreNetworkFlux Flux related to the pore network models
+     * \brief Flux related to the pore newtwork models
+     */
     /*!
      * \ingroup Flux
      * \defgroup StaggeredFlux Flux related to the staggered scheme
@@ -602,3 +612,9 @@
       * \brief Two-phase (immiscible) flow
       * For a detailed model description see porenetwork/2p/model.hh
       */
+
+ /* ***************** TimeStepping ******************/
+ /*!
+  * \defgroup TimeStepping Time stepping
+  * \brief The time stepping
+  */
diff --git a/dumux/discretization/porenetwork/fvelementgeometry.hh b/dumux/discretization/porenetwork/fvelementgeometry.hh
index 70243b7569bbdbfaebd6ed22e854cbbdc3f3f523..269ee1c665e8fff8f7568c1a8c1a7cbe5c94b64c 100644
--- a/dumux/discretization/porenetwork/fvelementgeometry.hh
+++ b/dumux/discretization/porenetwork/fvelementgeometry.hh
@@ -18,7 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief Base class for the local geometry for porenetworks
  */
 #ifndef DUMUX_DISCRETIZATION_PNM_FV_ELEMENT_GEOMETRY_HH
@@ -31,7 +31,7 @@
 namespace Dumux::PoreNetwork {
 
 /*!
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief Base class for the local geometry for porenetworks
  * \tparam GG the finite volume grid geometry type
  * \tparam enableFVGridGeometryCache if the grid geometry is cached or not
diff --git a/dumux/discretization/porenetwork/gridgeometry.hh b/dumux/discretization/porenetwork/gridgeometry.hh
index 31cc117aedd8de4aae2c7530a49b4cc266a10e9e..c790bbb5a68a5949849b69f530aa77e8d4b1b026 100644
--- a/dumux/discretization/porenetwork/gridgeometry.hh
+++ b/dumux/discretization/porenetwork/gridgeometry.hh
@@ -18,7 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief Base class for the finite volume geometry for porenetwork models
  */
 #ifndef DUMUX_DISCRETIZATION_PNM_GRID_GEOMETRY_HH
@@ -459,7 +459,7 @@ private:
 };
 
 /*!
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief The default traits
  * \tparam the grid view type
  */
@@ -669,7 +669,7 @@ private:
 };
 
 /*!
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief Base class for the finite volume geometry for porenetwork models
  * \note For caching disabled we store only some essential index maps to build up local systems on-demand in
  *       the corresponding FVElementGeometry
diff --git a/dumux/discretization/porenetwork/subcontrolvolume.hh b/dumux/discretization/porenetwork/subcontrolvolume.hh
index 3434e0920c3743145b6dce8ad626a7e71a4cdaa4..e5d1f5eb84cbc3141897530894b0bf2c5713eaf8 100644
--- a/dumux/discretization/porenetwork/subcontrolvolume.hh
+++ b/dumux/discretization/porenetwork/subcontrolvolume.hh
@@ -18,7 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief the sub control volume for pore networks
  */
 #ifndef DUMUX_DISCRETIZATION_PNM_SUBCONTROLVOLUME_HH
@@ -32,7 +32,7 @@
 namespace Dumux::PoreNetwork {
 
 /*!
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief Default traits class
  * \tparam GV the type of the grid view
  */
@@ -53,7 +53,7 @@ struct PNMDefaultScvGeometryTraits
 };
 
 /*!
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief the sub control volume for porenetworks
  * \tparam GV the type of the grid view
  * \tparam T the scv geometry traits
diff --git a/dumux/discretization/porenetwork/subcontrolvolumeface.hh b/dumux/discretization/porenetwork/subcontrolvolumeface.hh
index 220c9b24f5347593d933dd8c93a93513ec9205c7..83c5a882a54a04d45ed6b943a1ed4cbf83c32e65 100644
--- a/dumux/discretization/porenetwork/subcontrolvolumeface.hh
+++ b/dumux/discretization/porenetwork/subcontrolvolumeface.hh
@@ -18,7 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief Base class for a sub control volume face
  */
 #ifndef DUMUX_DISCRETIZATION_PNM_SUBCONTROLVOLUMEFACE_HH
@@ -30,7 +30,7 @@
 namespace Dumux::PoreNetwork {
 
 /*!
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkDiscretization
  * \brief Default traits class
  * \tparam GV the type of the grid view
  */
diff --git a/dumux/flux/porenetwork/advection.hh b/dumux/flux/porenetwork/advection.hh
index 14dc8b0da376d6a50b853ed625f86c1d25f590a0..3ffd4180f337dd1ec213f6f99864d33e782ded5a 100644
--- a/dumux/flux/porenetwork/advection.hh
+++ b/dumux/flux/porenetwork/advection.hh
@@ -18,7 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkFlux
  * \brief This file contains the data which is required to calculate
  *        the fluxes of the pore network model over a face of a finite volume.
  */
@@ -39,7 +39,7 @@ namespace Dumux::PoreNetwork {
 
 /*!
  * \file
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkFlux
  * \brief Hagen–Poiseuille-type flux law to describe the advective flux for pore-network models.
  */
 template<class ScalarT, class... TransmissibilityLawTypes>
diff --git a/dumux/flux/porenetwork/fickslaw.hh b/dumux/flux/porenetwork/fickslaw.hh
index a6a4f4f4f3a0d3b46185f048c86b0e9a231c88e4..b22f7074337503abfea0c8d8cd66174552fba7a3 100644
--- a/dumux/flux/porenetwork/fickslaw.hh
+++ b/dumux/flux/porenetwork/fickslaw.hh
@@ -18,7 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkFlux
  * \brief This file contains the data which is required to calculate
  *        diffusive mass fluxes due to molecular diffusion with Fick's law.
  */
@@ -33,7 +33,7 @@
 namespace Dumux::PoreNetwork {
 
 /*!
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkFlux
  * \brief Specialization of Fick's Law for the pore-network model.
  */
 template<class Scalar, int numPhases, int numComponents,
diff --git a/dumux/flux/porenetwork/fourierslaw.hh b/dumux/flux/porenetwork/fourierslaw.hh
index 2f091f6a20db667fce4a24f20ba5c3b608aed6cd..a40a96dcdf9284933268f2af6816463800ada8d5 100644
--- a/dumux/flux/porenetwork/fourierslaw.hh
+++ b/dumux/flux/porenetwork/fourierslaw.hh
@@ -18,7 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
- * \ingroup PoreNetworkModels
+ * \ingroup PoreNetworkFlux
  * \brief This file contains the data which is required to calculate
  *        diffusive heat fluxes with Fourier's law.
  */
@@ -38,7 +38,7 @@ struct NoDiffusionType {};
 } // end namespace Detail
 
  /*!
-  * \ingroup PoreNetworkModels
+  * \ingroup PoreNetworkFlux
   * \brief Specialization of Fourier's Law for the pore-network model.
   */
 template<class MolecularDiffusionType = Detail::NoDiffusionType>
diff --git a/dumux/timestepping/multistagemethods.hh b/dumux/timestepping/multistagemethods.hh
index ab4b284ad781fab97cb13799ac7d19ad39bf5709..1a2a7275e99a9cf0fba6ed7cb96b8df76998024b 100644
--- a/dumux/timestepping/multistagemethods.hh
+++ b/dumux/timestepping/multistagemethods.hh
@@ -18,6 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
+ * \ingroup TimeStepping
  * \brief Parameters for different multistage time stepping methods
  * \note See e.g. https://en.wikipedia.org/wiki/List_of_Runge%E2%80%93Kutta_methods
  */
diff --git a/dumux/timestepping/multistagetimestepper.hh b/dumux/timestepping/multistagetimestepper.hh
index 7759ee0113e26d53d17384f424193b31fb90dffb..53c1ce1524a49c49dadf6351ae5206ba57f0b1db 100644
--- a/dumux/timestepping/multistagetimestepper.hh
+++ b/dumux/timestepping/multistagetimestepper.hh
@@ -18,6 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
+ * \ingroup TimeStepping
  * \brief A time stepper performing a single time step of a transient simulation
  */
 #ifndef DUMUX_TIMESTEPPING_MULTISTAGE_TIMESTEPPER_HH
diff --git a/dumux/timestepping/timelevel.hh b/dumux/timestepping/timelevel.hh
index 1e6f777022991b014fb90208bd8c59b0720ba540..d82324c7bcc11f89f456f97d77ed533b96fa683f 100644
--- a/dumux/timestepping/timelevel.hh
+++ b/dumux/timestepping/timelevel.hh
@@ -18,6 +18,7 @@
  *****************************************************************************/
 /*!
  * \file
+ * \ingroup TimeStepping
  * \brief Class that represents a time level during time integration.
  */
 #ifndef DUMUX_TIMESTEPPING_TIME_LEVEL_HH