diff --git a/src/derivatives/common-data-types.md b/src/derivatives/common-data-types.md
index 63f0809c55..60f8657a64 100644
--- a/src/derivatives/common-data-types.md
+++ b/src/derivatives/common-data-types.md
@@ -180,8 +180,9 @@ Template:
 ```Text
 <pipeline_name>/
     sub-<label>/
-        <datatype>/
-            <source_entities>[_space-<space>][_desc-<label>]_<suffix>.<extension>
+        [ses-<label>/]
+            <datatype>/
+                <source_entities>[_space-<space>][_desc-<label>]_<suffix>.<extension>
 ```
 
 Data is considered to be *preprocessed* or *cleaned* if the data type of the input,
diff --git a/src/derivatives/imaging.md b/src/derivatives/imaging.md
index 4ba975824f..9a486ff955 100644
--- a/src/derivatives/imaging.md
+++ b/src/derivatives/imaging.md
@@ -10,8 +10,9 @@ Template:
 ```Text
 <pipeline_name>/
     sub-<label>/
-        <datatype>/
-            <source_entities>[_space-<space>][_res-<label>][_den-<label>][_desc-<label>]_<suffix>.<extension>
+        [ses-<label>/]
+            <datatype>/
+                <source_entities>[_space-<space>][_res-<label>][_den-<label>][_desc-<label>]_<suffix>.<extension>
 ```
 
 Volumetric preprocessing does not modify the number of dimensions, and so
@@ -147,8 +148,10 @@ Template:
 ```Text
 <pipeline_name>/
     sub-<label>/
-        anat|func|dwi/
-            <source_entities>[_space-<space>][_res-<label>][_den-<label>][_label-<label>][_desc-<label>]_mask.nii.gz
+        [ses-<label>/]
+            anat|func|dwi/
+                <source_entities>[_space-<space>][_res-<label>][_label-<label>][_desc-<label>]_mask.json
+                <source_entities>[_space-<space>][_res-<label>][_label-<label>][_desc-<label>]_mask.nii[.gz]
 ```
 
 A binary (1 - inside, 0 - outside) mask in the space defined by the [`space` entity](../appendices/entities.md#space).
@@ -264,8 +267,11 @@ Template:
 ```Text
 <pipeline_name>/
     sub-<label>/
-        anat|func|dwi/
-            <source_entities>[_space-<space>][_seg-<label>][_res-<label>][_den-<label>]_dseg.nii.gz
+        [ses-<label>/]
+            anat|func|dwi/
+                <source_entities>[_space-<space>][_seg-<label>][_res-<label>][_desc-<label>]_dseg.json
+                <source_entities>[_space-<space>][_seg-<label>][_res-<label>][_desc-<label>]_dseg.nii[.gz]
+                <source_entities>[_space-<space>][_seg-<label>][_res-<label>][_desc-<label>]_dseg.tsv
 ```
 
 Example:
@@ -328,8 +334,10 @@ Template:
 ```Text
 <pipeline_name>/
     sub-<label>/
-        func|anat|dwi/
-            <source_entities>[_space-<space>][_seg-<label>][_res-<label>][_den-<label>][_label-<label>]_probseg.nii.gz
+        [ses-<label>/]
+            func|anat|dwi/
+                <source_entities>[_space-<space>][_seg-<label>][_res-<label>][_label-<label>][_desc-<label>]_probseg.json
+                <source_entities>[_space-<space>][_seg-<label>][_res-<label>][_label-<label>][_desc-<label>]_probseg.nii[.gz]
 ```
 
 Example:
@@ -402,8 +410,12 @@ Template:
 ```Text
 <pipeline_name>/
     sub-<label>/
-        anat/
-            <source_entities>[_hemi-{L|R}][_space-<space>][_seg-<label>][_res-<label>][_den-<label>]_dseg.{label.gii|dlabel.nii}
+        [ses-<label>/]
+            anat/
+                <source_entities>[_hemi-{L|R}][_space-<space>][_seg-<label>][_res-<label>][_den-<label>][_desc-<label>]_dseg.json
+                <source_entities>[_hemi-{L|R}][_space-<space>][_seg-<label>][_den-<label>][_desc-<label>]_dseg.label.gii
+                <source_entities>[_hemi-{L|R}][_space-<space>][_seg-<label>][_res-<label>][_den-<label>][_desc-<label>]_dseg.dlabel.nii
+                <source_entities>[_hemi-{L|R}][_space-<space>][_seg-<label>][_res-<label>][_den-<label>][_desc-<label>]_dseg.tsv
 ```
 
 The [`hemi-<label>`](../appendices/entities.md#hemi) entity is REQUIRED for GIFTI files storing information about
diff --git a/src/schema/rules/files/deriv/imaging.yaml b/src/schema/rules/files/deriv/imaging.yaml
index 07f7678115..42be22dc23 100644
--- a/src/schema/rules/files/deriv/imaging.yaml
+++ b/src/schema/rules/files/deriv/imaging.yaml
@@ -52,7 +52,6 @@ anat_parametric_mask:
     $ref: rules.files.raw.anat.parametric.entities
     space: optional
     resolution: optional
-    density: optional
     label: optional
     description: optional
 
@@ -64,7 +63,6 @@ anat_nonparametric_mask:
     $ref: rules.files.raw.anat.nonparametric.entities
     space: optional
     resolution: optional
-    density: optional
     label: optional
     description: optional
 
@@ -72,11 +70,14 @@ dwi_mask:
   $ref: rules.files.raw.dwi.dwi
   suffixes:
     - mask
+  extensions:
+    - .nii.gz
+    - .nii
+    - .json
   entities:
     $ref: rules.files.raw.dwi.dwi.entities
     space: optional
     resolution: optional
-    density: optional
     label: optional
     description: optional
 
@@ -88,7 +89,6 @@ func_mask:
     $ref: rules.files.raw.func.func.entities
     space: optional
     resolution: optional
-    density: optional
     label: optional
     description: optional
 
@@ -99,8 +99,8 @@ anat_parametric_discrete_segmentation:
   entities:
     $ref: rules.files.raw.anat.parametric.entities
     space: optional
+    segmentation: optional
     resolution: optional
-    density: optional
     description: optional
   extensions:
     - .nii.gz
@@ -115,8 +115,8 @@ anat_nonparametric_discrete_segmentation:
   entities:
     $ref: rules.files.raw.anat.nonparametric.entities
     space: optional
+    segmentation: optional
     resolution: optional
-    density: optional
     description: optional
   extensions:
     - .nii.gz
@@ -131,9 +131,14 @@ func_discrete_segmentation:
   entities:
     $ref: rules.files.raw.func.func.entities
     space: optional
+    segmentation: optional
     resolution: optional
-    density: optional
     description: optional
+  extensions:
+    - .nii.gz
+    - .nii
+    - .json
+    - .tsv
 
 dwi_discrete_segmentation:
   $ref: rules.files.raw.dwi.dwi
@@ -143,8 +148,12 @@ dwi_discrete_segmentation:
     $ref: rules.files.raw.dwi.dwi.entities
     space: optional
     resolution: optional
-    density: optional
     description: optional
+  extensions:
+    - .nii.gz
+    - .nii
+    - .json
+    - .tsv
 
 anat_parametric_probabilistic_segmentation:
   $ref: rules.files.raw.anat.parametric
@@ -153,8 +162,8 @@ anat_parametric_probabilistic_segmentation:
   entities:
     $ref: rules.files.raw.anat.parametric.entities
     space: optional
+    segmentation: optional
     resolution: optional
-    density: optional
     label: optional
     description: optional
 
@@ -165,8 +174,8 @@ anat_nonparametric_probabilistic_segmentation:
   entities:
     $ref: rules.files.raw.anat.nonparametric.entities
     space: optional
+    segmentation: optional
     resolution: optional
-    density: optional
     label: optional
     description: optional
 
@@ -177,8 +186,8 @@ func_probabilistic_segmentation:
   entities:
     $ref: rules.files.raw.func.func.entities
     space: optional
+    segmentation: optional
     resolution: optional
-    density: optional
     label: optional
     description: optional
 
@@ -189,12 +198,16 @@ dwi_probabilistic_segmentation:
   entities:
     $ref: rules.files.raw.dwi.dwi.entities
     space: optional
+    segmentation: optional
     resolution: optional
-    density: optional
     label: optional
     description: optional
+  extensions:
+    - .nii.gz
+    - .nii
+    - .json
 
-anat_parametic_discrete_surface:
+anat_parametric_discrete_surface:
   $ref: rules.files.raw.anat.parametric
   suffixes:
     - dseg
@@ -207,11 +220,12 @@ anat_parametic_discrete_surface:
     $ref: rules.files.raw.anat.parametric.entities
     hemisphere: optional
     space: optional
+    segmentation: optional
     resolution: optional
     density: optional
     description: optional
 
-anat_nonparametic_discrete_surface:
+anat_nonparametric_discrete_surface:
   $ref: rules.files.raw.anat.nonparametric
   suffixes:
     - dseg
@@ -224,6 +238,7 @@ anat_nonparametic_discrete_surface:
     $ref: rules.files.raw.anat.nonparametric.entities
     hemisphere: optional
     space: optional
+    segmentation: optional
     resolution: optional
     density: optional
     description: optional