diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index 7916648..c0fcb11 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -5,10 +5,11 @@
   - [Tokens](specification/tokens/readme.md)
 
     - [Token format](specification/tokens/token-format.md)
-    - [Operators](specification/tokens/operators.md)
-    - [Keywords](specification/tokens/keywords.md)
-    - [Identifiers](specification/tokens/identifiers.md)
-    - [Literals](specification/tokens/literals.md)
-    - [Brackets](specification/tokens/brackets.md)
+    - [Token Kinds](specification/tokens/token-kinds.md)
+      - [Operators](specification/tokens/kinds/operators.md)
+      - [Keywords](specification/tokens/kinds/keywords.md)
+      - [Identifiers](specification/tokens/kinds/identifiers.md)
+      - [Literals](specification/tokens/kinds/literals.md)
+      - [Brackets](specification/tokens/kinds/brackets.md)
 
   - [Examples](examples/readme.md)
diff --git a/src/specification/tokens/brackets.md b/src/specification/tokens/kinds/brackets.md
similarity index 100%
rename from src/specification/tokens/brackets.md
rename to src/specification/tokens/kinds/brackets.md
diff --git a/src/specification/tokens/identifiers.md b/src/specification/tokens/kinds/identifiers.md
similarity index 100%
rename from src/specification/tokens/identifiers.md
rename to src/specification/tokens/kinds/identifiers.md
diff --git a/src/specification/tokens/keywords.md b/src/specification/tokens/kinds/keywords.md
similarity index 100%
rename from src/specification/tokens/keywords.md
rename to src/specification/tokens/kinds/keywords.md
diff --git a/src/specification/tokens/literals.md b/src/specification/tokens/kinds/literals.md
similarity index 100%
rename from src/specification/tokens/literals.md
rename to src/specification/tokens/kinds/literals.md
diff --git a/src/specification/tokens/operators.md b/src/specification/tokens/kinds/operators.md
similarity index 100%
rename from src/specification/tokens/operators.md
rename to src/specification/tokens/kinds/operators.md
diff --git a/src/specification/tokens/token-format.md b/src/specification/tokens/token-format.md
index 01fe992..6997ac5 100644
--- a/src/specification/tokens/token-format.md
+++ b/src/specification/tokens/token-format.md
@@ -1 +1,28 @@
 # Token format
+
+[Token](https://github.com/SymboScript/SymboScript/blob/main/types/src/lexer.rs#L4-L15)
+
+```rust
+pub struct Token {
+    /// Token Type
+    pub kind: TokenKind,
+
+    /// Start offset in source
+    pub start: usize,
+
+    /// End offset in source
+    pub end: usize,
+
+    pub value: TokenValue,
+}
+```
+
+[TokenValue](https://github.com/SymboScript/SymboScript/blob/main/types/src/lexer.rs#L110-L114)
+
+```rust
+pub enum TokenValue {
+    None,
+    Number(f64),
+    String(String),
+}
+```
diff --git a/src/specification/tokens/token-kinds.md b/src/specification/tokens/token-kinds.md
new file mode 100644
index 0000000..fb5c2d4
--- /dev/null
+++ b/src/specification/tokens/token-kinds.md
@@ -0,0 +1,98 @@
+# Token Kinds
+
+This chapter describes the token kinds used in the spec.
+
+[Kinds](https://github.com/SymboScript/SymboScript/blob/main/types/src/lexer.rs#L18-L107)
+
+```rust
+pub enum TokenKind {
+    Eof, // end of file
+    Comment,
+    Unexpected,
+
+    Semicolon,
+    Comma,
+    Colon,
+    Dot,
+
+    // Operators
+    Plus,
+    Minus,
+    Star,
+    Slash,
+    Power,
+    Range,
+    Modulo,
+
+    // Bitwise operators (Keyword2Operator)
+    BitAnd,
+    BitOr,
+    BitNot,
+    BitXor,
+    BitLeftShift,
+    BitRightShift,
+
+    // Unary operators
+    PlusPlus,
+    MinusMinus,
+    Question,
+
+    // Logic operators (Keyword2Operator)
+    And,
+    Or,
+    Xor,
+    Not,
+
+    /// Assignments operators (+=, -=, *=, /=...)
+    Assign,
+    FormulaAssign,
+    PlusAssign,
+    MinusAssign,
+    MultiplyAssign,
+    DivideAssign,
+    PowerAssign,
+    ModuloAssign,
+
+    // Comparison operators
+    Equal,
+    NotEqual,
+    Less,
+    LessEqual,
+    Greater,
+    GreaterEqual,
+
+    // Brackets
+    LParen,
+    RParen,
+    LBrace,
+    RBrace,
+    LBracket,
+    RBracket,
+
+    // Identifiers
+    Identifier,
+
+    // Literals
+    Number,
+    Str,
+
+    // --- Keywords ---
+
+    // Keyword literals
+    True,
+    False,
+
+    // Keywords
+    If,
+    Else,
+    While,
+    For,
+    Loop,
+    Let,
+    Return,
+    Break,
+    Continue,
+    Function,
+    In,
+}
+```