diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 51903d8b..c6931ce8 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -33,6 +33,7 @@ the coding style is described here:
   - indent switch cases
   - preprocessor directives not intended
   - if macro comprises more than one line, indent
+  - no new line after `template<>`
 - prefer built-in types:
   - `bool`
   - `signed char` or `unsigned char` are 8-bit
@@ -81,6 +82,7 @@ just put your demo song in `demos/`! be noted there are some guidelines:
 
 - avoid Nintendo song covers.
 - avoid big label song covers.
+- avoid poor quality songs.
 
 # Finishing
 
diff --git a/src/engine/platform/tia.cpp b/src/engine/platform/tia.cpp
index bebc1ff2..ed556e4f 100644
--- a/src/engine/platform/tia.cpp
+++ b/src/engine/platform/tia.cpp
@@ -118,6 +118,7 @@ void DivPlatformTIA::tick(bool sysTick) {
     }
     if (chan[i].freqChanged || chan[i].keyOn || chan[i].keyOff) {
       if (chan[i].insChanged) {
+        // TODO: fix 10xx bug here
         if (!chan[i].std.wave.will) {
           chan[i].shape=4;
           rWrite(0x15+i,chan[i].shape);