diff --git a/content/2.md b/content/2.md
index 22ce5e1..6d0ac14 100644
--- a/content/2.md
+++ b/content/2.md
@@ -11,7 +11,7 @@ RAID protects you against one and only one thing: a disk failure.
 
 It does _not_ protect you against any of the following things:
 
-* Multiple disk failures beyond the RAID level chosen (e.g. both disks in a mirror, or 3 disks in a RAID-6).
+* Multiple disk failures beyond the RAID level chosen (e.g. both disks in a mirror, or 3 disks in a RAID-6), including possible [UREs](https://holtstrom.com/michael/blog/post/588/RAID-5-URE-Failures.html).
 * Failure of the RAID controller itself (especially when using hardware RAID), the computer running the RAID, or the environment (a flood, fire, theft, etc.).
 * Data corruption on-disk from filesystem bugs, cosmic rays, or minor hardware or firmware failures.
 * Malicious or accidental deletion or modification of files by yourself or another party, including viruses, bad application writes, or administrative mistakes (e.g. `rm`-ing the wrong file or `mkfs` on an existing filesystem).