diff --git a/docs/api/browser-window.md b/docs/api/browser-window.md
index 304c24c3a1f0..7bf02e6599e9 100644
--- a/docs/api/browser-window.md
+++ b/docs/api/browser-window.md
@@ -966,10 +966,10 @@ Same as `webContents.capturePage([rect, ]callback)`.
 
 * `url` String
 * `options` Object (optional)
-  * `httpReferrer` String - A HTTP Referrer url.
-  * `userAgent` String - A user agent originating the request.
-  * `extraHeaders` String - Extra headers separated by "\n"
-  * `postData` ([UploadRawData](structures/upload-raw-data.md) | [UploadFile](structures/upload-file.md) | [UploadFileSystem](structures/upload-file-system.md) | [UploadBlob](structures/upload-blob.md))[]
+  * `httpReferrer` String (optional) - A HTTP Referrer url.
+  * `userAgent` String (optional) - A user agent originating the request.
+  * `extraHeaders` String (optional) - Extra headers separated by "\n"
+  * `postData` ([UploadRawData](structures/upload-raw-data.md) | [UploadFile](structures/upload-file.md) | [UploadFileSystem](structures/upload-file-system.md) | [UploadBlob](structures/upload-blob.md))[] (optional)
 
 Same as `webContents.loadURL(url[, options])`.
 
diff --git a/docs/api/web-contents.md b/docs/api/web-contents.md
index 638851da9e57..322d8fba4c53 100644
--- a/docs/api/web-contents.md
+++ b/docs/api/web-contents.md
@@ -487,10 +487,10 @@ win.loadURL('http://github.com')
 
 * `url` URL
 * `options` Object (optional)
-  * `httpReferrer` String - A HTTP Referrer url.
-  * `userAgent` String - A user agent originating the request.
-  * `extraHeaders` String - Extra headers separated by "\n"
-  * `postData` ([UploadRawData](structures/upload-raw-data.md) | [UploadFile](structures/upload-file.md) | [UploadFileSystem](structures/upload-file-system.md) | [UploadBlob](structures/upload-blob.md))[]
+  * `httpReferrer` String (optional) - A HTTP Referrer url.
+  * `userAgent` String (optional) - A user agent originating the request.
+  * `extraHeaders` String (optional) - Extra headers separated by "\n"
+  * `postData` ([UploadRawData](structures/upload-raw-data.md) | [UploadFile](structures/upload-file.md) | [UploadFileSystem](structures/upload-file-system.md) | [UploadBlob](structures/upload-blob.md))[] (optional)
 
 Loads the `url` in the window. The `url` must contain the protocol prefix,
 e.g. the `http://` or `file://`. If the load should bypass http cache then
diff --git a/docs/api/web-view-tag.md b/docs/api/web-view-tag.md
index 884e4f39d9d7..78ed927abca9 100644
--- a/docs/api/web-view-tag.md
+++ b/docs/api/web-view-tag.md
@@ -262,10 +262,10 @@ webview.addEventListener('dom-ready', () => {
 
 * `url` URL
 * `options` Object (optional)
-  * `httpReferrer` String - A HTTP Referrer url.
-  * `userAgent` String - A user agent originating the request.
-  * `extraHeaders` String - Extra headers separated by "\n"
-  * `postData` ([UploadRawData](structures/upload-raw-data.md) | [UploadFile](structures/upload-file.md) | [UploadFileSystem](structures/upload-file-system.md) | [UploadBlob](structures/upload-blob.md))[]
+  * `httpReferrer` String (optional) - A HTTP Referrer url.
+  * `userAgent` String (optional) - A user agent originating the request.
+  * `extraHeaders` String (optional) - Extra headers separated by "\n"
+  * `postData` ([UploadRawData](structures/upload-raw-data.md) | [UploadFile](structures/upload-file.md) | [UploadFileSystem](structures/upload-file-system.md) | [UploadBlob](structures/upload-blob.md))[] (optional)
 
 Loads the `url` in the webview, the `url` must contain the protocol prefix,
 e.g. the `http://` or `file://`.