diff --git a/webassets/apidocs/openapi.yml b/webassets/apidocs/openapi.yml
index 3f83c43..54432c7 100644
--- a/webassets/apidocs/openapi.yml
+++ b/webassets/apidocs/openapi.yml
@@ -990,4 +990,8 @@ components:
         icon:
           type: string
           description: Icon, from the Font Awesome set. This is fairly opinionated but is here to help the Spothole web UI and Field Spotter. Does not include the "fa-" prefix.
-          example: tree
\ No newline at end of file
+          example: tree
+        ref_regex:
+          type: string
+          description: Regex that matches this SIG's reference IDs. Generally for Spothole's own internal use, clients probably won't need this.
+          example: "[A-Z]{2}\-\d+"
\ No newline at end of file