diff --git a/grammar.js b/grammar.js
index 848ec83..6d16c74 100644
--- a/grammar.js
+++ b/grammar.js
@@ -123,6 +123,7 @@ module.exports = grammar({
       ")",
     ),
 
+    // FIXME: simplify with 'soong_config_variable'?
     select_value: ($) => seq(
       field("type", alias(
         choice("product_variable", "release_variable", "variant"),
@@ -133,6 +134,7 @@ module.exports = grammar({
       ")",
     ),
 
+    // FIXME
     soong_config_variable: ($) => seq(
       field("type", alias("soong_config_variable", $.selection_type)),
       "(",