diff --git a/examples/FileType-example.yaml b/examples/FileType-example.yaml
index 0899a69..ba5e385 100644
--- a/examples/FileType-example.yaml
+++ b/examples/FileType-example.yaml
@@ -14,6 +14,9 @@ subject:
 associated_instruments:
     - Example Machine
     - Bunch of Junk
+associated_file_extensions:
+    - dat
+    - txt
 associated_software:
     - Example Software
     - Bitrot Software
diff --git a/examples/FileType-netcdf.yaml b/examples/FileType-netcdf.yaml
index 84eb013..76f7c81 100644
--- a/examples/FileType-netcdf.yaml
+++ b/examples/FileType-netcdf.yaml
@@ -11,8 +11,9 @@ associated_vendors:
     - UCAR
 subject:
     - climatology
-    - meteorology
-    - oceanography
+    - meteorology - oceanography
+associated_file_extensions:
+    - nc
 associated_software:
     - ArcGIS
     - OriginPro
diff --git a/schemas/filetype.yaml b/schemas/filetype.yaml
index 9fe6212..6c89d83 100644
--- a/schemas/filetype.yaml
+++ b/schemas/filetype.yaml
@@ -48,6 +48,13 @@ classes:
                 description: >-
                     A list of any known software (proprietary or otherwise) that produces
                     such `FileType`.
+            associated_file_extensions:
+                multivalued: true
+                description: >-
+                    A list of any known file extensions that files of this `FileType`
+                    are found with. These may be used as a hint for `FileType` detection.
+                    Should omit the leading `'.'`, e.g. 'json' or 'txt'.
+                pattern: ^[A-z,0-9]*[A-z,0-9]+$
             base_formats:
                 multivalued: true
                 range: FileType