diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index afc43c49..8e4599d9 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -76,6 +76,7 @@ additional guidelines:
     - I will run a test suite to make sure this is the case.
     - if something breaks, you might want to add a compatibility flag (this requires changing the format though).
 - do not use `#pragma once`.
+- do not memcmp() structs.
 - on a switch block, **always** put `default` last and not in any other position.
   - I have fear of some C/C++ compilers ignoring the rest of cases upon hitting default.
 
diff --git a/src/engine/instrument.cpp b/src/engine/instrument.cpp
index 8cda5917..2c792df0 100644
--- a/src/engine/instrument.cpp
+++ b/src/engine/instrument.cpp
@@ -60,6 +60,10 @@ void DivInstrument::putInsData2(SafeWriter* w, bool fui) {
   bool featureSU=false;
   bool featureES=false;
 
+  // almost 40 years of C++, and there still isn't a way to easily compare two structs.
+  // even Java, which many regard as having a slow runtime, has .equals().
+  
+
   blockEndSeek=w->tell();
   if (!fui) {
     w->seek(blockStartSeek,SEEK_SET);