mention spacing in card docs, fixes part of #24373

diff --git a/docs/4.0/components/card.md b/docs/4.0/components/card.md
index ec89d26cf6f834a55914622d472ca2cf0fa7b86e..af231903f758eee2a0eb46dbe82693b95defca7a 100644 (file)
--- a/docs/4.0/components/card.md
+++ b/docs/4.0/components/card.md
@@ -12,7 +12,7 @@ A **card** is a flexible and extensible content container. It includes options f
 
 ## Example
 
-Cards are built with as little markup and styles as possible, but still manage to deliver a ton of control and customization. Built with flexbox, they offer easy alignment and mix well with other Bootstrap components.
+Cards are built with as little markup and styles as possible, but still manage to deliver a ton of control and customization. Built with flexbox, they offer easy alignment and mix well with other Bootstrap components. They have no `margin` by default, so use [spacing utilities]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/spacing/) as needed.
 
 Below is an example of a basic card with mixed content and a fixed width. Cards have no fixed width to start, so they'll naturally fill the full width of its parent element. This is easily customized with our various [sizing options](#sizing).