Update index.md

Author: prigiattiperrut

src/connections/sources/catalog/libraries/website/javascript/index.md

@@ -838,6 +838,9 @@ So, for example, if somebody follows the link with above query string to your si
 
 Whenever the UTM parameters are no longer a part of the URL, Segment no longer includes them. For example, if the user goes to a new page within your website which does not contain these parameters, they will not be included in subsequent events. UTM parameters are non-persistent by default as they could potentially cause data accuracy problems. Here's an example of why: Say a user clicks on an ad and lands on your site. He navigates around and bookmarks an internal page - or maybe shares a link with a friend, who shares it with another friend. All those links would then point back to the same test utm_source as the initial referrer for any purchase.
 
+**Additional Note**:
+Segment does not validate UTM parameter names. This design supports the flexibility to track both standard parameters (e.g., utm_source, utm_medium) and custom parameters defined by users. As a result, all parameters present in the URL are collected as-is and added to the context field, without checks for naming conventions or validity.
+
 ## Analytics.js performance
 
 The Analytics.js library and all Destination libraries are loaded with the [HTML script `async` tag](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script#attr-async){:target="_blank"}. This also means that Segment fires methods asynchronously, so you should adjust your code accordingly if you require that events be sent from the browser in a specific order.