diff --git a/src/execution_context.cpp b/src/execution_context.cpp
index d98c73b..80bff36 100644
--- a/src/execution_context.cpp
+++ b/src/execution_context.cpp
@@ -24,8 +24,10 @@ thread_local
 detail::activation_record::ptr_t
 detail::activation_record::current_rec;
 
+// zero-initialization
 thread_local static std::size_t counter;
 
+// schwarz counter
 activation_record_initializer::activation_record_initializer() {
     if ( 0 == counter++) {
         activation_record::current_rec.reset( new activation_record() );
@@ -42,6 +44,7 @@ activation_record_initializer::~activation_record_initializer() {
 
 execution_context
 execution_context::current() noexcept {
+    // initialized the first time control passes; per thread
     thread_local static detail::activation_record_initializer initializer;
     return execution_context();
 }