diff --git a/voteslog/file.go b/voteslog/file.go
index 898cab7..22a0140 100644
--- a/voteslog/file.go
+++ b/voteslog/file.go
@@ -20,6 +20,14 @@ var ErrExists = errors.New("msg with such index already exists")
 
 const maxSegments = 5
 
+// FileVotesLog is used to store votes and msgs on disk.
+//
+// Log is append-only, so we can't delete records from it, but log is divided into segments, which are rotated (oldest deleted) when
+// segments number threshold is reached.
+// Log is divided into two parts: msgs log and votes log. Each part has its own index, which is used to find record by its height.
+// Index is stored in memory and loaded from disk on startup.
+//
+// This code is intentionally monomorphized for msgs and votes, generics can slow the app and make code more complicated.
 type FileVotesLog struct {
 	// append-only log with proposed messages that node consumed
 	msgs *os.File