From a1966d76c3cb3eb4984868db195b4f4dc2917d64 Mon Sep 17 00:00:00 2001
From: Heiko Schaefer <heiko@schaefer.name>
Date: Fri, 20 May 2022 10:16:04 +0200
Subject: [PATCH] Add more information about YubiKey touch policy support (from
 `ykman/openpgp.py`).

---
 openpgp-card/src/card_do.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/openpgp-card/src/card_do.rs b/openpgp-card/src/card_do.rs
index f37aae3..303ab3c 100644
--- a/openpgp-card/src/card_do.rs
+++ b/openpgp-card/src/card_do.rs
@@ -313,6 +313,9 @@ impl Display for UIF {
 /// This setting is used in 4.4.3.6 User Interaction Flag (UIF)
 ///
 /// See spec pg 24 and <https://github.com/Yubico/yubikey-manager/blob/main/ykman/openpgp.py>
+///
+/// Touch policies were introduced in YubiKey Version 4.2.0 with modes ON, OFF and FIXED.
+/// YubiKey Version >= 5.2.1 added support for modes CACHED and CACHED_FIXED.
 #[non_exhaustive]
 pub enum TouchPolicy {
     Off,