diff --git a/middle.mkd b/middle.mkd
index f09d85f..373aca2 100644
--- a/middle.mkd
+++ b/middle.mkd
@@ -1058,6 +1058,7 @@ The value of the subpacket type octet may be:
32 Embedded Signature
33 Issuer Fingerprint
34 Preferred AEAD Algorithms
+ 35 Intended Recipient Fingerprint
100 to 110 Private or experimental
An implementation SHOULD ignore any subpacket of a type that it does
@@ -1662,6 +1663,19 @@ signature, the key ID of the Issuer subpacket MUST match the low
Note that the length N of the fingerprint for a version 4 key is 20
octets; for a version 5 key N is 32.
+#### Intended Recipient Fingerprint
+
+(1 octet key version number, N octets of fingerprint)
+
+The OpenPGP Key fingerprint of the intended recipient primary key. If
+one or more subpackets of this type are included in a signature, it
+SHOULD be considered valid only in an encrypted context, where the key
+it was encrypted to is one of the indicated primary keys, or one of
+their subkeys. This can be used to prevent forwarding a signature
+outside of its intended, encrypted context.
+
+Note that the length N of the fingerprint for a version 4 key is 20
+octets; for a version 5 key N is 32.
### {5.2.4} Computing Signatures