diff --git a/gc-notes.txt b/gc-notes.txt
index 39dcec43..278db935 100644
--- a/gc-notes.txt
+++ b/gc-notes.txt
@@ -7,8 +7,6 @@ Phase 6 (gc-dev6) - Multiple mutators (application threads)
 Phase 7 (TBD) - Sharing of variables between threads (ideally without limitation, but that might not be realistic)
 
 TODO:
-- need a legitimate test program that uses mutexes. am worried that when lock calls into a cont, the program will crash because it returns a boolean object, which the runtime does not handle
-  maybe just a simple producer/consumer type program
 
 - multiple mutators, and threading functions/types.  probably want this on a new branch, when ready
   part of this is implementing the beginnings of srfi-18, to create multiple threads, sync them, etc
@@ -20,6 +18,8 @@ TODO:
 
 - bring exceptions into local thread data? anything else?
   also, will probably need to lock shared resources such as I/O...
+- document at a high level how the GC works
+  mostly what minor/major GC's are, and how they are interleaved.
 - user manual
   need to document everything, including:
   - how to use cyclone (meta files, compiling modules, etc)