diff --git a/src/common-principles.md b/src/common-principles.md
index 0a42e4a885..3bf804ab53 100644
--- a/src/common-principles.md
+++ b/src/common-principles.md
@@ -540,6 +540,7 @@ and a guide for using macros can be found at
         "Units": "RECOMMENDED",
         "Delimiter": "OPTIONAL",
         "TermURL": "RECOMMENDED",
+        "ContextURI": "RECOMMENDED",
         "HED": "OPTIONAL",
    }
 ) }}
@@ -592,6 +593,20 @@ like in the example below.
 }
 ```
 
+The `ContextURI` can be used to provide a URL to a controlled vocabulary or ontology, or simply to provide a URL to a page that provides more context for the values in the column.
+It is to be used, so if combined with the value in that value (`<label>` or `<index>`), it would establish a unique identifier for the entity to be used across BIDS datasets.
+In the example below it would establish that `participant_id` is shared across datasets of the center, which would allow to differentiate center's subjects apart from subject ids used by other datasets used in the lab.
+
+```JSON
+{
+    "participant_id": {
+        "Description": "Unique identifier used for study subjects in the lab across studies",
+        "ContextURI": "https://thelab.example.com/term/subject/"
+    }
+}
+```
+
+
 ### Compressed tabular files
 
 Large tabular information, such as physiological recordings, MUST be stored with
diff --git a/src/modality-agnostic-files.md b/src/modality-agnostic-files.md
index b93ee17638..e835c7cfb5 100644
--- a/src/modality-agnostic-files.md
+++ b/src/modality-agnostic-files.md
@@ -267,6 +267,9 @@ to date of birth.
 
 ```JSON
 {
+    "participant_id": {
+        "ContextURI": "http://thelab.example.com/term/subject/"
+    },
     "age": {
         "Description": "age of the participant",
         "Units": "year"
@@ -422,7 +425,7 @@ about the questionnaire and `adhd_b` and `adhd_c_dx` correspond to individual
 columns.
 
 In addition to the keys available to describe columns in all tabular files
-(`LongName`, `Description`, `Levels`, `Units`, and `TermURL`) the
+(`LongName`, `Description`, `Levels`, `Units`, `TermURL`, and `ContextURI`) the
 `participants.json` file as well as phenotypic files can also include column
 descriptions with a `Derivative` field that, when set to true, indicates that
 values in the corresponding column is a transformation of values from other
diff --git a/src/schema/objects/metadata.yaml b/src/schema/objects/metadata.yaml
index f97f629589..2f5f96c629 100644
--- a/src/schema/objects/metadata.yaml
+++ b/src/schema/objects/metadata.yaml
@@ -519,6 +519,15 @@ Columns:
   type: array
   items:
     type: string
+ContextURI:
+  name: ContextURI
+  display_name: Context URI
+  description: |
+    URI establishing the context for the values of this data.
+    For example, https://thelab.example.com/term/subject/ if used for "participant_id"
+    could be used to non-ambigously link participant data acquisitions across datasets.
+  type: string
+  format: uri
 ContinuousHeadLocalization:
   name: ContinuousHeadLocalization
   display_name: Continuous Head Localization