diff --git a/book/source/adv/certificates.md b/book/source/adv/certificates.md
index b33a1de..305ac34 100644
--- a/book/source/adv/certificates.md
+++ b/book/source/adv/certificates.md
@@ -295,7 +295,7 @@ Keyserver designs have adapted to these challenges. For example, the keys.openpg
 
 Furthermore, KOO, Hockeypuck keyserver software, and Sequoia's `sq` command-line tool have plans to support or already support 1pa3pc, demonstrating the community's proactive stance on enhancing certificate security. See how [KOO supports 1pa3pc](https://gitlab.com/keys.openpgp.org/hagrid/-/commit/39c0e12ac64588220d36bada6497d8396f5915b3), [Hockeypuck's statement on "HIP 1: Regaining control over public key identity with authenticated key management"](https://github.com/hockeypuck/hockeypuck/wiki/HIP-1:-Regaining-control-over-public-key-identity-with-authenticated-key-management) and [Sequoia's support](https://man.archlinux.org/man/sq-key-attest-certifications.1)).
 
-It's also noteworthy that the mechanism of 1pa3pc relies on the *attested certifications* signature subpacket (type ID 37), a feature presently proposed in the draft-ietf-openpgp-rfc4880bis. Although the inclusion of this specific subpacket was not within the scope of the current "crypto-refresh" work by the OpenPGP working group, there is optimism that future revisions of the standard will formally integrate this capability, further solidifying the framework for secure and controlled certificate management.
+It's also noteworthy that the mechanism of 1pa3pc relies on the *attested certifications* signature subpacket (type ID `37`), a feature presently proposed in the draft-ietf-openpgp-rfc4880bis. Although the inclusion of this specific subpacket was not within the scope of the current "crypto-refresh" work by the OpenPGP working group, there is optimism that future revisions of the standard will formally integrate this capability, further solidifying the framework for secure and controlled certificate management.
 
 (social-graph-metadata-leak)=
 ### Metadata leak of social graph