diff --git a/src/aud/exam/prep/SequenceProcessor.java b/src/aud/exam/prep/SequenceProcessor.java
index f2d2636..858a657 100644
--- a/src/aud/exam/prep/SequenceProcessor.java
+++ b/src/aud/exam/prep/SequenceProcessor.java
@@ -71,7 +71,8 @@ public interface SequenceProcessor<T, S> {
     /**
      * Check whether ot not the given sequence is "valid" according to
      * what is considered valid depends on the specific data structure.
-     * This is also used by the tests.
+     * This is also used by the tests to verify implementations.
+     * This has to be tested separate for each data structure.
      *
      * @param s A sequence
      * @return true iff the given sequence is valid