diff --git a/docs/icon-design-guide.md b/docs/icon-design-guide.md
index 85d704971..7a1af86d9 100644
--- a/docs/icon-design-guide.md
+++ b/docs/icon-design-guide.md
@@ -55,6 +55,8 @@ Here are rules that should be followed to keep quality and consistency when maki
 
 Before an icon is added to the library, we like to have readable and optimized svg code.
 
+Never use [`<use>`](https://developer.mozilla.org/en-US/docs/Web/SVG/Element/use). While it may sometimes seem like a good way to optimize file size, there's no way to ensure that the referenced element IDs will be unique once the SVGs are embedded in HTML documents.
+
 ### Global Attributes
 
 For each icon these attributes are applied, corresponding to the above rules.