Update index.md

files/en-us/web/html/element/pre/index.md

@@ -7,7 +7,10 @@ browser-compat: html.elements.pre
 
 {{HTMLSidebar}}
 
-The **`<pre>`** [HTML](/en-US/docs/Web/HTML) element represents preformatted text which is to be presented exactly as written in the HTML file. The text is typically rendered using a non-proportional, or [monospaced](https://en.wikipedia.org/wiki/Monospaced_font), font. Whitespace inside this element is displayed as written.
+The **`<pre>`** [HTML](/en-US/docs/Web/HTML) element represents preformatted text which is to be presented exactly as written in the HTML file. The text is typically rendered using a non-proportional, or [monospaced](https://en.wikipedia.org/wiki/Monospaced_font) font. Whitespace inside this element is displayed as written.
+
+> [!NOTE]
+> A leading newline character immediately following the pre element start tag is stripped.
 
 By default, `<pre>` is a [block-level](/en-US/docs/Glossary/Block-level_content) element, i.e. its default {{cssxref("display")}} value is `block`.