[MISC] Move section on sessions.tsv file: longitudinal files -> modality agnostic files

src/02-common-principles.md

@@ -152,6 +152,20 @@ correspond to a unique identifier of that subject, such as `01`.
 The same holds for the `session` entity with its `ses-` key and its `<label>`
 value.
 
+Session labels MUST consist only of alphanumeric characters `[a-zA-Z0-9]`
+and SHOULD be consistent across subjects.
+If numbers are used in session labels we RECOMMEND using zero padding
+(for example `ses-01`, `ses-11` instead of `ses-1`, `ses-11`). This makes
+results of alphabetical sorting more intuitive. Acquisition time of session can
+be defined in the [sessions file](03-modality-agnostic-files.md#sessions-file).
+
+The extra session layer (at least one `/ses-<label>` subfolder) SHOULD
+be added for all subjects if at least one subject in the dataset has more than
+one session.
+If a `/ses-<label>` subfolder is included as part of the directory hierarchy,
+then the same [`ses-<label>`](./99-appendices/09-entities.md#ses)
+key/value pair MUST also be included as part of the file names themselves.
+
 A chain of entities, followed by a suffix, connected by underscores (`_`)
 produces a human readable file name, such as `sub-01_task-rest_eeg.edf`.
 It is evident from the file name alone that the file contains resting state

src/03-modality-agnostic-files.md

@@ -256,8 +256,9 @@ to date of birth.
 Template:
 
 ```Text
-phenotype/<measurement_tool_name>.tsv
-phenotype/<measurement_tool_name>.json
+phenotype/
+          <measurement_tool_name>.tsv
+          <measurement_tool_name>.json
 ```
 
 Optional: Yes
@@ -329,9 +330,10 @@ questionnaire).
 Template:
 
 ```Text
-sub-<label>/[ses-<label>/]
-    sub-<label>[_ses-<label>]_scans.tsv
-    sub-<label>[_ses-<label>]_scans.json
+sub-<label>/
+        [ses-<label>/]
+            sub-<label>[_ses-<label>]_scans.tsv
+            sub-<label>[_ses-<label>]_scans.json
 ```
 
 Optional: Yes
@@ -379,6 +381,34 @@ meg/sub-control01_task-rest_split-01_meg.nii.gz	1877-06-15T12:15:27
 meg/sub-control01_task-rest_split-02_meg.nii.gz	1877-06-15T12:15:27
 ```
 
+## Sessions file
+
+Template:
+
+```Text
+sub-<label>/
+            ses-<label>/
+            sub-<label>_sessions.tsv
+```
+
+Optional: Yes
+
+In case of multiple sessions there is an option of adding additional
+`sessions.tsv` files describing variables changing between sessions.
+In such case one file per participant SHOULD be added.
+These files MUST include a `session_id` column and describe each session by one and only one row.
+Column names in `sessions.tsv` files MUST be different from group level participant key column names in the
+[`participants.tsv` file](./03-modality-agnostic-files.md#participants-file).
+
+`_sessions.tsv` example:
+
+```Text
+session_id  acq_time  systolic_blood_pressure
+ses-predrug 2009-06-15T13:45:30 120
+ses-postdrug  2009-06-16T13:45:30 100
+ses-followup  2009-06-17T13:45:30 110
+```
+
 ## Code
 
 Template: `code/*`

src/06-longitudinal-and-multi-site-studies.md

@@ -2,20 +2,6 @@
 
 Multiple sessions (visits) are encoded by adding an extra layer of directories
 and file names in the form of `ses-<label>`.
-Session labels MUST consist only of alphanumeric characters `[a-zA-Z0-9]`
-and SHOULD be consistent across subjects.
-If numbers are used in session labels we RECOMMEND using zero padding
-(for example `ses-01`, `ses-11` instead of `ses-1`, `ses-11`). This makes
-results of alphabetical sorting more intuitive. Acquisition time of session can
-be defined in the [sessions file](#sessions-file).
-
-The extra session layer (at least one `/ses-<label>` subfolder) SHOULD
-be added for all subjects if at least one subject in the dataset has more than
-one session.
-If a `/ses-<label>` subfolder is included as part of the directory hierarchy,
-then the same [`ses-<label>`](./99-appendices/09-entities.md#ses)
-key/value pair MUST also be
-included as part of the file names themselves.
 
 ```Text
 sub-control01/
@@ -61,33 +47,6 @@ README
 CHANGES
 ```
 
-## Sessions file
-
-Template:
-
-```Text
-sub-<label>/
-    sub-<label>_sessions.tsv
-```
-
-Optional: Yes
-
-In case of multiple sessions there is an option of adding additional
-`sessions.tsv` files describing variables changing between sessions.
-In such case one file per participant SHOULD be added.
-These files MUST include a `session_id` column and describe each session by one and only one row.
-Column names in `sessions.tsv` files MUST be different from group level participant key column names in the
-[`participants.tsv` file](./03-modality-agnostic-files.md#participants-file).
-
-`_sessions.tsv` example:
-
-```Text
-session_id  acq_time  systolic_blood_pressure
-ses-predrug 2009-06-15T13:45:30 120
-ses-postdrug  2009-06-16T13:45:30 100
-ses-followup  2009-06-17T13:45:30 110
-```
-
 ## Multi-site or multi-center studies
 
 This version of the BIDS specification does not explicitly cover studies with