diff --git a/sop-java/src/main/java/sop/operation/DetachInbandSignatureAndMessage.java b/sop-java/src/main/java/sop/operation/DetachInbandSignatureAndMessage.java
index 46bd3f77..9e22258c 100644
--- a/sop-java/src/main/java/sop/operation/DetachInbandSignatureAndMessage.java
+++ b/sop-java/src/main/java/sop/operation/DetachInbandSignatureAndMessage.java
@@ -11,6 +11,9 @@ import java.io.InputStream;
 import sop.ReadyWithResult;
 import sop.Signatures;
 
+/**
+ * Split cleartext signed messages up into data and signatures.
+ */
 public interface DetachInbandSignatureAndMessage {
 
     /**