diff --git a/book/source/adv/certificates.md b/book/source/adv/certificates.md
index 312c231..6dd7d11 100644
--- a/book/source/adv/certificates.md
+++ b/book/source/adv/certificates.md
@@ -204,7 +204,7 @@ Overall, certificate minimization for email presents a promising approach to enh
 
     The process significantly reduces the certificate size from 152,322 bytes to just 3,771 bytes, demonstrating a substantial decrease in size by over 40 times. Such minimization is particularly crucial in contexts with strict size limitations, like embedding certificate data in email headers.
 
-## Identifying certificates: By Fingerprints, Key IDs on email address
+## Identifying certificates: By Fingerprints, Key IDs, or email address
 
 OpenPGP certificates are often identified through fingerprints and Key IDs, both of which are derived from the public key material. Over time, OpenPGP's approach to identifying certificates through fingerprints and key IDs has adapted to changing demands.