diff --git a/TODO.md b/TODO.md
index f9febf7..57c4900 100644
--- a/TODO.md
+++ b/TODO.md
@@ -2,6 +2,7 @@
 
 Features which need to be created before v0.1.0 release.
 
-- Improve graceful error handling when parsing files
-- Finalize configuration file scheme
-- Implement identifiers
+- [ ] Improve graceful error handling when parsing files
+- [ ] Finalize configuration file scheme
+- [x] Implement identifiers
+- [ ] Handle case when files already exist