diff --git a/CHANGELOG.md b/CHANGELOG.md
index 519f178..456be30 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # Changelog
 
+- Add documentation for 'mode' field in FileInfo.
+
 ## Unreleased
 
 ## v2.3.0 - 24 June 2025
diff --git a/src/simplifile.gleam b/src/simplifile.gleam
index 4bdabab..f908e3b 100644
--- a/src/simplifile.gleam
+++ b/src/simplifile.gleam
@@ -184,6 +184,15 @@ pub type FileInfo {
     /// File size in bytes.
     size: Int,
     /// File mode that indicates the file type and its permissions.
+    ///
+    /// This field enocodes file type and permissions in a 16 bit int in
+    /// the following order
+    /// - bits 15-12: File Type. e.g RegularFile, Symlink, Directory
+    /// - bits 11-9 : Special file permissions such as setUserId, setGroupId, and the Sticky-bit
+    /// - bits 8-6  : User read, write, and execute permisions.
+    /// - bits 5-3  : Group read, write, and execute permissions.
+    /// - bits 2-0  : Other read, write, and execute permissions.
+    ///
     /// For example, in Unix and Linux, a mode value of 33188 indicates
     /// a regular file and the permissions associated with it
     /// (read and write for the owner, and read-only for others, in