diff --git a/src/04-modality-specific-files/07-behavioral-experiments.md b/src/04-modality-specific-files/07-behavioral-experiments.md
index 71a7d941eb..0f2435ac53 100644
--- a/src/04-modality-specific-files/07-behavioral-experiments.md
+++ b/src/04-modality-specific-files/07-behavioral-experiments.md
@@ -5,14 +5,14 @@ Template:
 ```Text
 sub-<label>/[ses-<label>/]
     beh/
-        sub-<label>[_ses-<label>]_task-<label>_events.tsv
-        sub-<label>[_ses-<label>]_task-<label>_events.json
-        sub-<label>[_ses-<label>]_task-<label>_beh.tsv
-        sub-<label>[_ses-<label>]_task-<label>_beh.json
-        sub-<label>[_ses-<label>]_task-<label>_physio.tsv.gz
-        sub-<label>[_ses-<label>]_task-<label>_physio.json
-        sub-<label>[_ses-<label>]_task-<label>_stim.tsv.gz
-        sub-<label>[_ses-<label>]_task-<label>_stim.json
+        sub-<label>[_ses-<label>]_task-<label>[_acq-<label>][_run-<index>]_events.tsv
+        sub-<label>[_ses-<label>]_task-<label>[_acq-<label>][_run-<index>]_events.json
+        sub-<label>[_ses-<label>]_task-<label>[_acq-<label>][_run-<index>]_beh.tsv
+        sub-<label>[_ses-<label>]_task-<label>[_acq-<label>][_run-<index>]_beh.json
+        sub-<label>[_ses-<label>]_task-<label>[_acq-<label>][_run-<index>][_recording-<label>]_physio.tsv.gz
+        sub-<label>[_ses-<label>]_task-<label>[_acq-<label>][_run-<index>][_recording-<label>]_physio.json
+        sub-<label>[_ses-<label>]_task-<label>[_acq-<label>][_run-<index>][_recording-<label>]_stim.tsv.gz
+        sub-<label>[_ses-<label>]_task-<label>[_acq-<label>][_run-<index>][_recording-<label>]_stim.json
 ```
 
 In addition to logs from behavioral experiments performed alongside imaging data
@@ -26,3 +26,9 @@ as for tasks performed during MRI, electrophysiological or other neural recordin
 Additionally, events files that do not include the mandatory `onset` and
 `duration` columns can still be included, but should be labeled `_beh.tsv`
 rather than `_events.tsv`.
+
+The OPTIONAL `acq-<label>` key/value pair corresponds to a custom label to
+distinguish different conditions present during multiple runs of the same task.
+For example, if a study includes runs of an n-back task, with deep brain
+stimulation turned on or off, the data files may be labelled
+`sub-01_task-nback_acq-dbson_beh.tsv` and `sub-01_task-nback_acq-dbsoff_beh.tsv`.
diff --git a/src/99-appendices/04-entity-table.md b/src/99-appendices/04-entity-table.md
index 5a36dd9059..e460e28488 100644
--- a/src/99-appendices/04-entity-table.md
+++ b/src/99-appendices/04-entity-table.md
@@ -20,13 +20,14 @@ A general introduction to entities is given in the section on
 | dwi<br>(dwi bvec bval)                                                                         | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                | OPTIONAL                 | OPTIONAL      |                        |                |                     |                       |                 |                 |
 | fmap<br>(phasediff phase1 phase2 magnitude1 magnitude2 magnitude fieldmap)                     | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
 | fmap<br>(epi)                                                                                  | REQUIRED      | OPTIONAL      |                | OPTIONAL      | OPTIONAL                 |                | REQUIRED                 | OPTIONAL      |                        |                |                     |                       |                 |                 |
-| beh<br>(events stim physio)                                                                    | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          |               |                        |                |                     |                       |                 |                 |
+| beh<br>(beh events)                                                                            | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
+| beh<br>(stim physio)                                                                           | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                | OPTIONAL            |                       |                 |                 |
 | meg<br>                                                                                        | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     | OPTIONAL              |                 | OPTIONAL        |
 | eeg<br>                                                                                        | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
 | ieeg<br>                                                                                       | REQUIRED      | OPTIONAL      | REQUIRED       | OPTIONAL      |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
 | channels<br>(meg/eeg/ieeg)                                                                     | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |
 | headshape<br>(meg)                                                                             | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |                 |
 | markers<br>(meg)                                                                               | REQUIRED      | OPTIONAL      | OPTIONAL       | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |                 |
-| photo<br>(meg/eeg/ieeg)                                                                        | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       |                 |                 |        
+| photo<br>(meg/eeg/ieeg)                                                                        | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       |                 |                 |
 | electrodes<br>(eeg/ieeg)                                                                       | REQUIRED      | OPTIONAL      |                | OPTIONAL      |                          |                |                          |               |                        |                |                     |                       | OPTIONAL        |                 |
-| events<br>(meg/eeg/ieeg)                                                                       | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |        
+| events<br>(meg/eeg/ieeg)                                                                       | REQUIRED      | OPTIONAL      | REQUIRED       |               |                          |                |                          | OPTIONAL      |                        |                |                     |                       |                 |                 |