diff --git a/spec3.json b/spec3.json
index 4dbf2ee..8600d5e 100644
--- a/spec3.json
+++ b/spec3.json
@@ -6598,13 +6598,15 @@
                   "title": {
                     "type": "string",
                     "maxLength": 255,
-                    "description": "An optional title that overrides the document title on the publicly shared page."
+                    "nullable": true,
+                    "description": "Override title displayed on the publicly shared page. If not set the source document or collection title is used."
                   },
                   "iconUrl": {
                     "type": "string",
                     "format": "uri",
                     "maxLength": 4096,
-                    "description": "An optional icon URL that overrides the workspace branding on the publicly shared page."
+                    "nullable": true,
+                    "description": "URL of an icon to display on the publicly shared page, overriding the workspace branding."
                   }
                 },
                 "required": [
@@ -9053,13 +9055,15 @@
           "title": {
             "type": "string",
             "maxLength": 255,
-            "description": "An optional title that overrides the document title on the publicly shared page."
+            "nullable": true,
+            "description": "Override title displayed on the publicly shared page. If not set the source document or collection title is used."
           },
           "iconUrl": {
             "type": "string",
             "format": "uri",
             "maxLength": 4096,
-            "description": "An optional icon URL that overrides the workspace branding on the publicly shared page."
+            "nullable": true,
+            "description": "URL of an icon displayed on the publicly shared page, overriding the workspace branding."
           },
           "published": {
             "type": "boolean",
diff --git a/spec3.yml b/spec3.yml
index 6bf89ad..0d0540c 100644
--- a/spec3.yml
+++ b/spec3.yml
@@ -4585,14 +4585,18 @@ paths:
                 title:
                   type: string
                   maxLength: 255
-                  description: An optional title that overrides the document title
-                    on the publicly shared page.
+                  nullable: true
+                  description:
+                    Override title displayed on the publicly shared page. If
+                    not set the source document or collection title is used.
                 iconUrl:
                   type: string
                   format: uri
                   maxLength: 4096
-                  description: An optional icon URL that overrides the workspace
-                    branding on the publicly shared page.
+                  nullable: true
+                  description:
+                    URL of an icon to display on the publicly shared page,
+                    overriding the workspace branding.
               required:
                 - id
                 - published
@@ -6289,14 +6293,18 @@ components:
         title:
           type: string
           maxLength: 255
-          description: An optional title that overrides the document title on the
-            publicly shared page.
+          nullable: true
+          description:
+            Override title displayed on the publicly shared page. If not set
+            the source document or collection title is used.
         iconUrl:
           type: string
           format: uri
           maxLength: 4096
-          description: An optional icon URL that overrides the workspace branding
-            on the publicly shared page.
+          nullable: true
+          description:
+            URL of an icon displayed on the publicly shared page, overriding
+            the workspace branding.
         published:
           type: boolean
           example: false