diff --git a/README.md b/README.md
index d61b4a2..5506876 100644
--- a/README.md
+++ b/README.md
@@ -103,12 +103,12 @@ CherryUSB Host Stack has the following functions：
 - Automatic loading of supported Class drivers
 - Support blocking transfers and asynchronous transfers
 - Support Composite Device
-- Multi-level HUB support, expandable up to 7 levels(Testing hub with 10 ports works well)
+- Multi-level HUB support, expandable up to 7 levels(Testing hub with 10 ports works well,only support dwc2 and ehci now)
 - Support Communication Device Class (CDC_ACM, CDC_ECM)
 - Support Human Interface Device (HID)
 - Support Mass Storage Class (MSC)
-- Support USB Video CLASS
-- Support USB Audio CLASS
+- Support USB Video CLASS (commercial charge)
+- Support USB Audio CLASS (commercial charge)
 - Support Remote NDIS (RNDIS)
 - Support USB Bluetooth class (support nimble and zephyr bluetooth stack, support **CLASS:0xE0** or vendor class like cdc acm)
 - Support Vendor class
diff --git a/README_zh.md b/README_zh.md
index ca0d69e..e1bdbd5 100644
--- a/README_zh.md
+++ b/README_zh.md
@@ -101,12 +101,12 @@ CherryUSB Host 协议栈当前实现以下功能：
 - 自动加载支持的Class 驱动
 - 支持阻塞式传输和异步传输
 - 支持复合设备
-- 支持多级 HUB,最高可拓展到 7 级(目前测试 1拖 10 没有问题)
+- 支持多级 HUB,最高可拓展到 7 级(目前测试 1拖 10 没有问题，当前仅支持 dwc2 和 ehci)
 - 支持 Communication Device Class (CDC_ACM, CDC_ECM)
 - 支持 Human Interface Device (HID)
 - 支持 Mass Storage Class (MSC)
-- Support USB Video CLASS
-- Support USB Audio CLASS
+- Support USB Video CLASS（商业收费）
+- Support USB Audio CLASS（商业收费）
 - 支持 Remote NDIS (RNDIS)
 - 支持 USB Bluetooth (支持 nimble and zephyr bluetooth 协议栈，支持 **CLASS: 0xE0** 或者厂家自定义类，类似于 cdc acm 功能)
 - 支持 Vendor 类 class