From 3ab7319afea86485212e72557a4538166f316d2b Mon Sep 17 00:00:00 2001
From: inokawa <48897392+inokawa@users.noreply.github.com>
Date: Sat, 18 Jan 2025 15:40:02 +0900
Subject: [PATCH] Update README.md

---
 README.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/README.md b/README.md
index 88fb30dd..97514eea 100644
--- a/README.md
+++ b/README.md
@@ -329,6 +329,10 @@ It may be dispatched by ResizeObserver in this lib [as described in spec](https:
 
 Especially for `webpack-dev-server`, [you can filter out the specific error with `devServer.client.overlay.runtimeErrors` option](https://webpack.js.org/configuration/dev-server/#overlay).
 
+#### Why my items are squashed on resize/add/remove?
+
+Maybe you forgot to pass `key` prop to each items, or the keys are not unique. Item sizes are stored per key.
+
 #### Why `VListHandle.viewportSize` is 0 on mount?
 
 `viewportSize` will be calculated by ResizeObserver so it's 0 until the first measurement.