diff --git a/source/dll_main.cpp b/source/dll_main.cpp
index f3a40bc..aa8f57b 100644
--- a/source/dll_main.cpp
+++ b/source/dll_main.cpp
@@ -274,6 +274,8 @@ extern "C" __declspec(dllexport) int __cdecl RemoveFile(const wchar_t* path)
     }
 }
 
+// nullptr first arg = return required size
+// returns paths separated by null terminator, e.g. "C:\foo.tpf\0C:\bar.zip\0\0"
 extern "C" __declspec(dllexport) int __cdecl GetFiles(wchar_t* buffer, const size_t buffer_size_chars)
 {
     try {