diff --git a/cpp/ql/src/semmle/code/cpp/exprs/Expr.qll b/cpp/ql/src/semmle/code/cpp/exprs/Expr.qll
index 941046c8f73..c43cc441d64 100644
--- a/cpp/ql/src/semmle/code/cpp/exprs/Expr.qll
+++ b/cpp/ql/src/semmle/code/cpp/exprs/Expr.qll
@@ -207,7 +207,7 @@ class Expr extends StmtParent, @expr {
    * - "prvalue"
    * - "prvalue(load)"
    *
-   * The "prvalue*(load)" string is used when the expression is a *prvalue*, but
+   * The "prvalue(load)" string is used when the expression is a *prvalue*, but
    * `hasLValueToRvalueConversion()` holds.
    */
   string getValueCategoryString() {
@@ -278,7 +278,7 @@ class Expr extends StmtParent, @expr {
    *
    * See [basic.lval] in the C++ language specification.
    * In C++03, every expression is either an *lvalue* or an *rvalue*.
-   * In C++11, every expression is exactly one of an *lvalue*, an *xvalue*, or a *prvalue* (with *rvalue*s being the union of *xvalues* and *prvalue*s).
+   * In C++11, every expression is exactly one of an *lvalue*, an *xvalue*, or a *prvalue* (with *rvalue*s being the union of *xvalue*s and *prvalue*s).
    * Using the C++11 terminology, this predicate selects expressions whose value category is *lvalue*.
    */
   predicate isLValue() {
@@ -460,6 +460,8 @@ class Expr extends StmtParent, @expr {
 
 /**
  * A C/C++ operation.
+ *
+ * This is the QL abstract root class for all operations.
  */
 abstract class Operation extends Expr {
   /** Gets the operator of this operation. */
diff --git a/cpp/ql/src/semmle/code/cpp/exprs/Literal.qll b/cpp/ql/src/semmle/code/cpp/exprs/Literal.qll
index 84a8e91b393..3b890d9287a 100644
--- a/cpp/ql/src/semmle/code/cpp/exprs/Literal.qll
+++ b/cpp/ql/src/semmle/code/cpp/exprs/Literal.qll
@@ -2,6 +2,8 @@ import semmle.code.cpp.exprs.Expr
 
 /**
  * A C/C++ literal.
+ *
+ * The is the QL root class for all literals.
  */
 class Literal extends Expr, @literal {
   /** Gets a textual representation of this literal. */
@@ -26,9 +28,7 @@ class Literal extends Expr, @literal {
  * For example:
  * ```
  * void *label_ptr = &&myLabel; // &&myLabel is a LabelLiteral
- *
  * goto *label_ptr; // this is a ComputedGotoStmt
- *
  * myLabel: // this is a LabelStmt
  * ```
  */
@@ -84,7 +84,11 @@ abstract class TextLiteral extends Literal {
 }
 
 /**
- * A character literal, for example `'a'` or `L'a'`.
+ * A character literal.  For example:
+ * ```
+ * char c1 = 'a';
+ * wchar_t c2 = L'b';
+ * ```
  */
 class CharLiteral extends TextLiteral {
   CharLiteral() { this.getValueText().regexpMatch("(?s)\\s*L?'.*") }
@@ -98,7 +102,11 @@ class CharLiteral extends TextLiteral {
 }
 
 /**
- * A string literal, for example `"abcdef"` or `L"123456"`.
+ * A string literal. For example:
+ * ```
+ * const char *s1 = "abcdef";
+ * const wchar_t *s2 = L"123456";
+ * ```
  */
 class StringLiteral extends TextLiteral {
   StringLiteral() {
@@ -111,7 +119,11 @@ class StringLiteral extends TextLiteral {
 }
 
 /**
- * An octal literal.
+ * An octal literal. For example:
+ * ```
+ * char esc = 033;
+ * ```
+ * Octal literals must always start with the digit `0`.
  */
 class OctalLiteral extends Literal {
   OctalLiteral() { super.getValueText().regexpMatch("\\s*0[0-7]+[uUlL]*\\s*") }
@@ -121,6 +133,9 @@ class OctalLiteral extends Literal {
 
 /**
  * A hexadecimal literal.
+ * ```
+ * unsigned int32_t minus2 = 0xfffffffe;
+ * ```
  */
 class HexLiteral extends Literal {
   HexLiteral() { super.getValueText().regexpMatch("\\s*0[xX][0-9a-fA-F]+[uUlL]*\\s*") }
@@ -130,6 +145,8 @@ class HexLiteral extends Literal {
 
 /**
  * A C/C++ aggregate literal.
+ *
+ * For example:
  */
 class AggregateLiteral extends Expr, @aggregateliteral {
   override string getCanonicalQLClass() { result = "AggregateLiteral" }
@@ -153,7 +170,11 @@ class AggregateLiteral extends Expr, @aggregateliteral {
 }
 
 /**
- * A C/C++ aggregate literal that initializes a class, struct, or union
+ * A C/C++ aggregate literal that initializes a `class`, `struct`, or `union`.
+ * For example:
+ * ```
+ * S s = { arg1, arg2, { arg3, arg4 }, arg5 };
+ * ```
  */
 class ClassAggregateLiteral extends AggregateLiteral {
   Class classType;
@@ -271,6 +292,9 @@ class ArrayOrVectorAggregateLiteral extends AggregateLiteral {
 
 /**
  * A C/C++ aggregate literal that initializes an array
+ * ```
+ * S s[4] = { s_1, s_2, s_3, s_n };
+ * ```
  */
 class ArrayAggregateLiteral extends ArrayOrVectorAggregateLiteral {
   ArrayType arrayType;
@@ -286,6 +310,12 @@ class ArrayAggregateLiteral extends ArrayOrVectorAggregateLiteral {
 
 /**
  * A C/C++ aggregate literal that initializes a GNU vector type.
+ * ```
+ * typedef int v4si __attribute__ (( vector_size(4*sizeof(int)) ));
+ * v4si v = (v4si){ 1, 2, 3, 4 };
+ * typedef float float4 __attribute__((ext_vector_type(4)));
+ * float4 vf = {1.0f, 2.0f, 3.0f, 4.0f};
+ * ```
  */
 class VectorAggregateLiteral extends ArrayOrVectorAggregateLiteral {
   GNUVectorType vectorType;