diff --git a/content/v2.0/reference/key-concepts/data-elements.md b/content/v2.0/reference/key-concepts/data-elements.md
index 7fec5eaf8..b0e7b467a 100644
--- a/content/v2.0/reference/key-concepts/data-elements.md
+++ b/content/v2.0/reference/key-concepts/data-elements.md
@@ -107,6 +107,11 @@ location = portland, scientist = mullen
 Because tags are indexed, queries on tags are faster than queries on fields. This makes tags ideal for storing commonly-queried metadata.
 {{% /note %}}
 
+{{% note %}}
+Tags containing highly variable information like UUIDs, hashes, and random strings will lead to a large number of series in the database, known as **high series cardinality**. High series cardinality is a primary driver of high memory usage for many database workloads. See [series cardinality](v2.0/reference/glossary/#series-cardinality) for more information.   
+{{% /note %}}
+
+
 #### Why your schema matters
 
 If most of your queries focus on values in the fields, for example, a query to find when 23 bees were counted: