diff --git a/.skills/SKILL.md b/.skills/SKILL.md
index 0a6775f3..f208d0e2 100644
--- a/.skills/SKILL.md
+++ b/.skills/SKILL.md
@@ -898,7 +898,7 @@ rm -rf /path/to/sd/.crosspoint/epub_<hash>/sections/
 
 **Current Versions** (as of docs/file-formats.md):
 - `book.bin`: **Version 5** (metadata structure)
-- `section.bin`: **Version 12** (layout structure)
+- `section.bin`: **Version 24** (layout structure)
 
 **Version Increment Rules**:
 1. **ALWAYS increment version** BEFORE changing binary structure
@@ -908,7 +908,7 @@ rm -rf /path/to/sd/.crosspoint/epub_<hash>/sections/
 **Example** (incrementing section format version):
 ```cpp
 // lib/Epub/Epub/Section.cpp
-static constexpr uint8_t SECTION_FILE_VERSION = 13;  // Was 12, now 13
+static constexpr uint8_t SECTION_FILE_VERSION = 25;  // Was 24, now 25
 
 // Add new field to structure
 struct PageLine {
diff --git a/docs/file-formats.md b/docs/file-formats.md
index 1b7ca3b8..2d5116dc 100644
--- a/docs/file-formats.md
+++ b/docs/file-formats.md
@@ -2,7 +2,7 @@
 
 ## `book.bin`
 
-### Version 3
+### Version 5
 
 ImHex Pattern:
 
@@ -12,7 +12,7 @@ import std.string;
 import std.core;
 
 // === Configuration ===
-#define EXPECTED_VERSION 3
+#define EXPECTED_VERSION 5
 #define MAX_STRING_LENGTH 65535
 
 // === String Structure ===
@@ -34,6 +34,7 @@ fn format_string(String s) {
 struct Metadata {
     String title [[comment("Book title")]];
     String author [[comment("Book author")]];
+    String language [[comment("Book language code")]];
     String coverItemHref [[comment("Path to cover image")]];
     String textReferenceHref [[comment("Path to guided first text reference")]];
 } [[comment("Book metadata information")]];