diff --git a/Documentation/ProjectFile/material/fluid/i_fluid.md b/Documentation/ProjectFile/material/fluid/i_fluid.md
index 576add64edccf5d980a0ff86143dc43a7109a788..82d8c9d54553e63e79421d319e75d2acdc461388 100644
--- a/Documentation/ProjectFile/material/fluid/i_fluid.md
+++ b/Documentation/ProjectFile/material/fluid/i_fluid.md
@@ -1 +1 @@
-\ogs_missing_documentation
+Description of the fluid properties using constitutive relations.
diff --git a/Documentation/ProjectFile/material/solid/constitutive_relation/i_constitutive_relation.md b/Documentation/ProjectFile/material/solid/constitutive_relation/i_constitutive_relation.md
index 576add64edccf5d980a0ff86143dc43a7109a788..8edd2122296e2d58f781c598331929903aaf3933 100644
--- a/Documentation/ProjectFile/material/solid/constitutive_relation/i_constitutive_relation.md
+++ b/Documentation/ProjectFile/material/solid/constitutive_relation/i_constitutive_relation.md
@@ -1 +1 @@
-\ogs_missing_documentation
+Description of the solid properties using constitutive relations.
diff --git a/Documentation/ProjectFile/material/solid/constitutive_relation/t_type.md b/Documentation/ProjectFile/material/solid/constitutive_relation/t_type.md
index 576add64edccf5d980a0ff86143dc43a7109a788..df9ef9584f8fb1edc035d54811ee0abdbc332d7d 100644
--- a/Documentation/ProjectFile/material/solid/constitutive_relation/t_type.md
+++ b/Documentation/ProjectFile/material/solid/constitutive_relation/t_type.md
@@ -1 +1,4 @@
-\ogs_missing_documentation
+The constitutive relation type.
+See constitutive relation \ref
+ogs_file_param__material__solid__constitutive_relation "cases" for available
+options.
diff --git a/Documentation/ProjectFile/prj/processes/process/ComponentTransport/fluid b/Documentation/ProjectFile/prj/processes/process/ComponentTransport/fluid
new file mode 120000
index 0000000000000000000000000000000000000000..e482ed2ecc6ff32819ad2a01f85d637b707ec3c4
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/ComponentTransport/fluid
@@ -0,0 +1 @@
+../../../../material/fluid
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/ComponentTransport/fluid/i_fluid.md b/Documentation/ProjectFile/prj/processes/process/ComponentTransport/fluid/i_fluid.md
deleted file mode 100644
index 82d8c9d54553e63e79421d319e75d2acdc461388..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/ComponentTransport/fluid/i_fluid.md
+++ /dev/null
@@ -1 +0,0 @@
-Description of the fluid properties using constitutive relations.
diff --git a/Documentation/ProjectFile/prj/processes/process/HT/fluid b/Documentation/ProjectFile/prj/processes/process/HT/fluid
new file mode 120000
index 0000000000000000000000000000000000000000..e482ed2ecc6ff32819ad2a01f85d637b707ec3c4
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/HT/fluid
@@ -0,0 +1 @@
+../../../../material/fluid
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/HT/fluid/i_fluid.md b/Documentation/ProjectFile/prj/processes/process/HT/fluid/i_fluid.md
deleted file mode 100644
index 00aef4b95e01a85c9fb21ee4e2f36860cefd7dc1..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/HT/fluid/i_fluid.md
+++ /dev/null
@@ -1 +0,0 @@
-Defines fluid properties.
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation
new file mode 120000
index 0000000000000000000000000000000000000000..cfcb5e03bbe20c629c87a7f4d1fb7ac0fea2e1d3
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation
@@ -0,0 +1 @@
+../../../../material/solid/constitutive_relation
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation/i_constitutive_relation.md b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation/i_constitutive_relation.md
deleted file mode 100644
index 8e7925f0d029ab08752e52395c902df2725e52e9..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation/i_constitutive_relation.md
+++ /dev/null
@@ -1 +0,0 @@
-\copydoc ProcessLib::HydroMechanics::HydroMechanicsProcessData::material
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation/t_type.md b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation/t_type.md
deleted file mode 100644
index d7c7defae9637e69f0a97762bd68752fcf46bf75..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS/constitutive_relation/t_type.md
+++ /dev/null
@@ -1,3 +0,0 @@
-The type of constitutive relation. See
-ProcessLib::HydroMechanics::createHydroMechanicsProcess()
-for available implementations.
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation
new file mode 120000
index 0000000000000000000000000000000000000000..cfcb5e03bbe20c629c87a7f4d1fb7ac0fea2e1d3
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation
@@ -0,0 +1 @@
+../../../../material/solid/constitutive_relation
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation/i_constitutive_relation.md b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation/i_constitutive_relation.md
deleted file mode 100644
index 576add64edccf5d980a0ff86143dc43a7109a788..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation/i_constitutive_relation.md
+++ /dev/null
@@ -1 +0,0 @@
-\ogs_missing_documentation
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation/t_type.md b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation/t_type.md
deleted file mode 100644
index 576add64edccf5d980a0ff86143dc43a7109a788..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/constitutive_relation/t_type.md
+++ /dev/null
@@ -1 +0,0 @@
-\ogs_missing_documentation
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model
new file mode 120000
index 0000000000000000000000000000000000000000..74e127c90cd049410ccfa5e603e23bc3f824cde0
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model
@@ -0,0 +1 @@
+../../../../material/fracture_model
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model/i_fracture_model.md b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model/i_fracture_model.md
deleted file mode 100644
index b84270b45277ebf24709c46f416d3afe0a93d9b0..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model/i_fracture_model.md
+++ /dev/null
@@ -1 +0,0 @@
-Fracture models used in LIE/XFEM solvers.
diff --git a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model/t_type.md b/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model/t_type.md
deleted file mode 100644
index ff2deece14285d5751f66ff93a66a53f749fa474..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/HYDRO_MECHANICS_WITH_LIE/fracture_model/t_type.md
+++ /dev/null
@@ -1 +0,0 @@
-The fracture model type describing the fracture's opening and closing behaviour.
diff --git a/Documentation/ProjectFile/prj/processes/process/LIQUID_FLOW/material_property/fluid b/Documentation/ProjectFile/prj/processes/process/LIQUID_FLOW/material_property/fluid
new file mode 120000
index 0000000000000000000000000000000000000000..88198bcc260d8f91054c488eefa5fc3be8c8fda6
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/LIQUID_FLOW/material_property/fluid
@@ -0,0 +1 @@
+../../../../../material/fluid
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/LIQUID_FLOW/material_property/fluid/i_fluid.md b/Documentation/ProjectFile/prj/processes/process/LIQUID_FLOW/material_property/fluid/i_fluid.md
deleted file mode 100644
index b69f95391d20a64002c5e4d4aed6f38d93095e95..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/LIQUID_FLOW/material_property/fluid/i_fluid.md
+++ /dev/null
@@ -1 +0,0 @@
-Defines fluid properties of liquid phase.
diff --git a/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation b/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation
new file mode 120000
index 0000000000000000000000000000000000000000..cfcb5e03bbe20c629c87a7f4d1fb7ac0fea2e1d3
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation
@@ -0,0 +1 @@
+../../../../material/solid/constitutive_relation
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation/i_constitutive_relation.md b/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation/i_constitutive_relation.md
deleted file mode 100644
index 4a2457d3f4c6929e8670842215d3ab145424d306..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation/i_constitutive_relation.md
+++ /dev/null
@@ -1 +0,0 @@
-The constitutive relation for the brittle fracture.
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation/t_type.md b/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation/t_type.md
deleted file mode 100644
index c66714fc4af7a6a2e11c293f1bc98e75a4c7c09c..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/PHASE_FIELD/constitutive_relation/t_type.md
+++ /dev/null
@@ -1,2 +0,0 @@
-The type of constitutive relation available.
-1. Linear elastic
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/RICHARDS_FLOW/material_property/fluid b/Documentation/ProjectFile/prj/processes/process/RICHARDS_FLOW/material_property/fluid
new file mode 120000
index 0000000000000000000000000000000000000000..88198bcc260d8f91054c488eefa5fc3be8c8fda6
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/RICHARDS_FLOW/material_property/fluid
@@ -0,0 +1 @@
+../../../../../material/fluid
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/RICHARDS_FLOW/material_property/fluid/i_fluid.md b/Documentation/ProjectFile/prj/processes/process/RICHARDS_FLOW/material_property/fluid/i_fluid.md
deleted file mode 100644
index 00aef4b95e01a85c9fb21ee4e2f36860cefd7dc1..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/RICHARDS_FLOW/material_property/fluid/i_fluid.md
+++ /dev/null
@@ -1 +0,0 @@
-Defines fluid properties.
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation
new file mode 120000
index 0000000000000000000000000000000000000000..cfcb5e03bbe20c629c87a7f4d1fb7ac0fea2e1d3
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation
@@ -0,0 +1 @@
+../../../../material/solid/constitutive_relation
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation/i_constitutive_relation.md b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation/i_constitutive_relation.md
deleted file mode 100644
index 576add64edccf5d980a0ff86143dc43a7109a788..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation/i_constitutive_relation.md
+++ /dev/null
@@ -1 +0,0 @@
-\ogs_missing_documentation
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation/t_type.md b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation/t_type.md
deleted file mode 100644
index 576add64edccf5d980a0ff86143dc43a7109a788..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION/constitutive_relation/t_type.md
+++ /dev/null
@@ -1 +0,0 @@
-\ogs_missing_documentation
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation
new file mode 120000
index 0000000000000000000000000000000000000000..cfcb5e03bbe20c629c87a7f4d1fb7ac0fea2e1d3
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation
@@ -0,0 +1 @@
+../../../../material/solid/constitutive_relation
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation/i_constitutive_relation.md b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation/i_constitutive_relation.md
deleted file mode 100644
index 576add64edccf5d980a0ff86143dc43a7109a788..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation/i_constitutive_relation.md
+++ /dev/null
@@ -1 +0,0 @@
-\ogs_missing_documentation
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation/t_type.md b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation/t_type.md
deleted file mode 100644
index 576add64edccf5d980a0ff86143dc43a7109a788..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/constitutive_relation/t_type.md
+++ /dev/null
@@ -1 +0,0 @@
-\ogs_missing_documentation
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model
new file mode 120000
index 0000000000000000000000000000000000000000..74e127c90cd049410ccfa5e603e23bc3f824cde0
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model
@@ -0,0 +1 @@
+../../../../material/fracture_model
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model/i_fracture_model.md b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model/i_fracture_model.md
deleted file mode 100644
index b84270b45277ebf24709c46f416d3afe0a93d9b0..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model/i_fracture_model.md
+++ /dev/null
@@ -1 +0,0 @@
-Fracture models used in LIE/XFEM solvers.
diff --git a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model/t_type.md b/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model/t_type.md
deleted file mode 100644
index ff2deece14285d5751f66ff93a66a53f749fa474..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/SMALL_DEFORMATION_WITH_LIE/fracture_model/t_type.md
+++ /dev/null
@@ -1 +0,0 @@
-The fracture model type describing the fracture's opening and closing behaviour.
diff --git a/Documentation/ProjectFile/prj/processes/process/TWOPHASE_FLOW_PP/material_property/fluid b/Documentation/ProjectFile/prj/processes/process/TWOPHASE_FLOW_PP/material_property/fluid
new file mode 120000
index 0000000000000000000000000000000000000000..88198bcc260d8f91054c488eefa5fc3be8c8fda6
--- /dev/null
+++ b/Documentation/ProjectFile/prj/processes/process/TWOPHASE_FLOW_PP/material_property/fluid
@@ -0,0 +1 @@
+../../../../../material/fluid
\ No newline at end of file
diff --git a/Documentation/ProjectFile/prj/processes/process/TWOPHASE_FLOW_PP/material_property/fluid/i_fluid.md b/Documentation/ProjectFile/prj/processes/process/TWOPHASE_FLOW_PP/material_property/fluid/i_fluid.md
deleted file mode 100644
index 6f73cf4d6bfb9b1b683522a9a996b689e594cd06..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/prj/processes/process/TWOPHASE_FLOW_PP/material_property/fluid/i_fluid.md
+++ /dev/null
@@ -1 +0,0 @@
-Defines fluid properties of gas and liquid phases.
diff --git a/scripts/cmake/DocumentationProjectFile.cmake b/scripts/cmake/DocumentationProjectFile.cmake
index dc25ea1198b95644d1e038a9c3937b0197c32117..d88ef307306fce34189d268e62c3817d82a47568 100644
--- a/scripts/cmake/DocumentationProjectFile.cmake
+++ b/scripts/cmake/DocumentationProjectFile.cmake
@@ -131,7 +131,8 @@ if (IS_DIRECTORY ${DocumentationProjectFileBuildDir})
 endif()
 
 # traverse input file hierarchy
-file(GLOB_RECURSE input_paths ${DocumentationProjectFileInputDir}/c_* ${DocumentationProjectFileInputDir}/i_*)
+file(GLOB_RECURSE input_paths FOLLOW_SYMLINKS
+    ${DocumentationProjectFileInputDir}/c_* ${DocumentationProjectFileInputDir}/i_*)
 
 foreach(p ${input_paths})
     message("directory index file ${p}")
diff --git a/scripts/doc/linked-xml-file.py b/scripts/doc/linked-xml-file.py
index 616f66304e3bc788f41013bce40fa150ede6fc41..b0ebc07e6ca6c8a28e97bb77de25b46881c21892 100755
--- a/scripts/doc/linked-xml-file.py
+++ b/scripts/doc/linked-xml-file.py
@@ -38,8 +38,6 @@ outdir = os.path.join(docauxdir, "dox", "CTestProjectFiles")
 # "prj__processes__process": "process",
 # See the expansion table in the append-xml-tags.py too.
 tag_path_expansion_table = {
-        "prj__processes__process__constitutive_relation" : "material__solid__constitutive_relation",
-        "prj__processes__process__material_property" : "material",
         "material__porous_medium__porous_medium" : "material__porous_medium",
         }