diff --git a/README.md b/README.md
index b14ec34..c84633c 100644
--- a/README.md
+++ b/README.md
@@ -149,7 +149,7 @@ For example, `[!!success]` displays as "Success" with a checkmark icon. This wor
| syntax | details |
| ---------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- |
| \| | start pipe symbol |
-| `ICON` | name of icon. e.g. `lucide-dice` |
+| `ICON` | [Lucide icon](https://lucide.dev/icons/) name. e.g. `dice` or `lucide-dice` |
| \| | pipe symbol |
| `KEY:VAL` | `KEY` is the type or label, `VAL` is the value text displayed. e.g. `release:1.0.0` |
| \| | pipe symbol |
@@ -165,6 +165,9 @@ For example, `[!!success]` displays as "Success" with a checkmark icon. This wor
> `[!!|tag|:Release 1.2.1]`
> ```
+> [!IMPORTANT]
+> Custom syntax requires actual [Lucide icon](https://lucide.dev/icons/) names (e.g., `pen-tool`, `message-square`). The built-in aliases like `notice` or `success` only work with standard syntax. For example, use `[!!|pen-tool|notice:text|color]` not `[!!|notice|notice:text|color]`.
+
###### example
```markdown