diff --git a/extensions/notebook/src/extension.ts b/extensions/notebook/src/extension.ts
index 247572162c..e22d29adb0 100644
--- a/extensions/notebook/src/extension.ts
+++ b/extensions/notebook/src/extension.ts
@@ -26,6 +26,11 @@ type ChooseCellType = { label: string, id: CellType };
 export async function activate(extensionContext: vscode.ExtensionContext): Promise<IExtensionApi> {
 	const appContext = new AppContext(extensionContext);
 	const createBookPath: string = path.posix.join(extensionContext.extensionPath, 'resources', 'notebooks', 'JupyterBooksCreate.ipynb');
+	/**
+	 *  									***** IMPORTANT *****
+	 * If changes are made to bookTreeView.openBook, please ensure backwards compatibility with its current state.
+	 * This is the command used in the extension generator to open a Jupyter Book.
+	 */
 	extensionContext.subscriptions.push(vscode.commands.registerCommand('bookTreeView.openBook', (bookPath: string, openAsUntitled: boolean, urlToOpen?: string) => openAsUntitled ? providedBookTreeViewProvider.openBook(bookPath, urlToOpen, true) : bookTreeViewProvider.openBook(bookPath, urlToOpen, true)));
 	extensionContext.subscriptions.push(vscode.commands.registerCommand('bookTreeView.openNotebook', (resource) => bookTreeViewProvider.openNotebook(resource)));
 	extensionContext.subscriptions.push(vscode.commands.registerCommand('bookTreeView.openUntitledNotebook', (resource) => providedBookTreeViewProvider.openNotebookAsUntitled(resource)));