diff --git a/src/main/java/com/fasterxml/jackson/core/base/GeneratorBase.java b/src/main/java/com/fasterxml/jackson/core/base/GeneratorBase.java
index b3bbaca73b..4320a515bb 100644
--- a/src/main/java/com/fasterxml/jackson/core/base/GeneratorBase.java
+++ b/src/main/java/com/fasterxml/jackson/core/base/GeneratorBase.java
@@ -434,6 +434,9 @@ public void writeTree(TreeNode rootNode) throws IOException {
      * 
      * @param typeMsg Additional message used for generating exception message
      *   if value output is NOT legal in current generator output state.
+     *
+     * @throws IOException if there is either an underlying I/O problem or encoding
+     *    issue at format layer
      */
     protected abstract void _verifyValueWrite(String typeMsg) throws IOException;
 
@@ -441,6 +444,8 @@ public void writeTree(TreeNode rootNode) throws IOException {
      * Overridable factory method called to instantiate an appropriate {@link PrettyPrinter}
      * for case of "just use the default one", when {@link #useDefaultPrettyPrinter()} is called.
      *
+     * @return Instance of "default" pretty printer to use
+     *
      * @since 2.6
      */
     protected PrettyPrinter _constructDefaultPrettyPrinter() {
@@ -451,6 +456,12 @@ protected PrettyPrinter _constructDefaultPrettyPrinter() {
      * Helper method used to serialize a {@link java.math.BigDecimal} as a String,
      * for serialization, taking into account configuration settings
      *
+     * @param value BigDecimal value to convert to String
+     *
+     * @return String representation of {@code value}
+     *
+     * @throws IOException if there is a problem serializing value as String
+     *
      * @since 2.7.7
      */
     protected String _asString(BigDecimal value) throws IOException {
@@ -473,9 +484,7 @@ protected String _asString(BigDecimal value) throws IOException {
     /**********************************************************
      */
 
-    /**
-     * @since 2.5
-     */
+    // @since 2.5
     protected final int _decodeSurrogate(int surr1, int surr2) throws IOException
     {
         // First is known to be valid, but how about the other?
diff --git a/src/main/java/com/fasterxml/jackson/core/io/NumberInput.java b/src/main/java/com/fasterxml/jackson/core/io/NumberInput.java
index a154d33233..a93236bd72 100644
--- a/src/main/java/com/fasterxml/jackson/core/io/NumberInput.java
+++ b/src/main/java/com/fasterxml/jackson/core/io/NumberInput.java
@@ -19,11 +19,18 @@ public final class NumberInput
     final static String MAX_LONG_STR = String.valueOf(Long.MAX_VALUE);
 
     /**
-     * Fast method for parsing integers that are known to fit into
+     * Fast method for parsing unsigned integers that are known to fit into
      * regular 32-bit signed int type. This means that length is
-     * between 1 and 9 digits (inclusive)
+     * between 1 and 9 digits (inclusive) and there is no sign character.
      *<p>
-     * Note: public to let unit tests call it
+     * Note: public to let unit tests call it; not meant to be used by any
+     * code outside this package.
+     *
+     * @param ch Buffer that contains integer value to decode
+     * @param off Offset of the first digit character in buffer
+     * @param len Length of the number to decode (in characters)
+     *
+     * @return Decoded {@code int} value
      */
     public static int parseInt(char[] ch, int off, int len)
     {
@@ -52,7 +59,16 @@ public static int parseInt(char[] ch, int off, int len)
 
     /**
      * Helper method to (more) efficiently parse integer numbers from
-     * String values.
+     * String values. Input String must be simple Java integer value.
+     * No range checks are made to verify that the value fits in 32-bit Java {@code int}:
+     * caller is expected to only calls this in cases where this can be guaranteed
+     * (basically: number of digits does not exceed 9)
+     *<p>
+     * NOTE: semantics differ significantly from {@link #parseInt(char[], int, int)}.
+     *
+     * @param s String that contains integer value to decode
+     *
+     * @return Decoded {@code int} value
      */
     public static int parseInt(String s)
     {
@@ -115,6 +131,13 @@ public static long parseLong(char[] ch, int off, int len)
         return val + (long) parseInt(ch, off+len1, 9);
     }
 
+    /**
+     * Similar to {@link #parseInt(String)} but for {@code long} values.
+     *
+     * @param s String that contains {@code long} value to decode
+     *
+     * @return Decoded {@code long} value
+     */
     public static long parseLong(String s)
     {
         // Ok, now; as the very first thing, let's just optimize case of "fake longs";
@@ -133,8 +156,14 @@ public static long parseLong(String s)
      * Note that input String must NOT contain leading minus sign (even
      * if 'negative' is set to true).
      *
+     * @param ch Buffer that contains long value to check
+     * @param off Offset of the first digit character in buffer
+     * @param len Length of the number to decode (in characters)
      * @param negative Whether original number had a minus sign (which is
      *    NOT passed to this method) or not
+     *
+     * @return {@code True} if specified String representation is within Java
+     *   {@code long} range; {@code false} if not.
      */
     public static boolean inLongRange(char[] ch, int off, int len,
             boolean negative)
@@ -157,8 +186,12 @@ public static boolean inLongRange(char[] ch, int off, int len,
      * Similar to {@link #inLongRange(char[],int,int,boolean)}, but
      * with String argument
      *
+     * @param s String that contains {@code long} value to check
      * @param negative Whether original number had a minus sign (which is
      *    NOT passed to this method) or not
+     *
+     * @return {@code True} if specified String representation is within Java
+     *   {@code long} range; {@code false} if not.
      */
     public static boolean inLongRange(String s, boolean negative)
     {
diff --git a/src/main/java/com/fasterxml/jackson/core/io/NumberOutput.java b/src/main/java/com/fasterxml/jackson/core/io/NumberOutput.java
index 1649b91b29..187a0b4e4c 100644
--- a/src/main/java/com/fasterxml/jackson/core/io/NumberOutput.java
+++ b/src/main/java/com/fasterxml/jackson/core/io/NumberOutput.java
@@ -21,9 +21,8 @@ public final class NumberOutput
     private final static int[] TRIPLET_TO_CHARS = new int[1000];
 
     static {
-        /* Let's fill it with NULLs for ignorable leading digits,
-         * and digit chars for others
-         */
+        // Let's fill it with NULLs for ignorable leading digits,
+        // and digit chars for others
         int fullIx = 0;
         for (int i1 = 0; i1 < 10; ++i1) {
             for (int i2 = 0; i2 < 10; ++i2) {
@@ -51,7 +50,17 @@ public final class NumberOutput
      */
 
     /**
-     * @return Offset within buffer after outputting int
+     * Method for appending value of given {@code int} value into
+     * specified {@code char[]}.
+     *<p>
+     * NOTE: caller must guarantee that the output buffer has enough room
+     * for String representation of the value.
+     *
+     * @param v Value to append to buffer
+     * @param b Buffer to append value to: caller must guarantee there is enough room
+     * @param off Offset within output buffer ({@code b}) to append number at
+     *
+     * @return Offset within buffer after outputting {@code int}
      */
     public static int outputInt(int v, char[] b, int off)
     {
@@ -152,7 +161,17 @@ public static int outputInt(int v, byte[] b, int off)
     }
 
     /**
-     * @return Offset within buffer after outputting int
+     * Method for appending value of given {@code long} value into
+     * specified {@code char[]}.
+     *<p>
+     * NOTE: caller must guarantee that the output buffer has enough room
+     * for String representation of the value.
+     *
+     * @param v Value to append to buffer
+     * @param b Buffer to append value to: caller must guarantee there is enough room
+     * @param off Offset within output buffer ({@code b}) to append number at
+     *
+     * @return Offset within buffer after outputting {@code long}
      */
     public static int outputLong(long v, char[] b, int off)
     {
@@ -258,9 +277,7 @@ public static String toString(double v) {
         return Double.toString(v);
     }
 
-    /**
-     * @since 2.6.0
-     */
+    // @since 2.6
     public static String toString(float v) {
         return Float.toString(v);
     }
@@ -275,6 +292,8 @@ public static String toString(float v) {
      * Helper method to verify whether given {@code double} value is finite
      * (regular rational number} or not (NaN or Infinity).
      *
+     * @param value {@code double} value to check
+     *
      * @return True if number is NOT finite (is Infinity or NaN); false otherwise
      *
      * Since 2.10
@@ -288,6 +307,8 @@ public static boolean notFinite(double value) {
      * Helper method to verify whether given {@code float} value is finite
      * (regular rational number} or not (NaN or Infinity).
      *
+     * @param value {@code float} value to check
+     *
      * @return True if number is NOT finite (is Infinity or NaN); false otherwise
      *
      * Since 2.10
diff --git a/src/main/java/com/fasterxml/jackson/core/io/UTF8Writer.java b/src/main/java/com/fasterxml/jackson/core/io/UTF8Writer.java
index 8feb45d824..0521d25975 100644
--- a/src/main/java/com/fasterxml/jackson/core/io/UTF8Writer.java
+++ b/src/main/java/com/fasterxml/jackson/core/io/UTF8Writer.java
@@ -354,6 +354,10 @@ public void write(String str, int off, int len)  throws IOException
      * Method called to calculate Unicode code-point, from a surrogate pair.
      *
      * @param secondPart Second UTF-16 unit of surrogate (first part stored in {@code _surrogate})
+     *
+     * @return Decoded Unicode point
+     *
+     * @throws IOException If surrogate pair is invalid
      */
     protected int convertSurrogate(int secondPart)
         throws IOException
diff --git a/src/main/java/com/fasterxml/jackson/core/json/ByteSourceJsonBootstrapper.java b/src/main/java/com/fasterxml/jackson/core/json/ByteSourceJsonBootstrapper.java
index ce4ce11cd5..2639364c6e 100644
--- a/src/main/java/com/fasterxml/jackson/core/json/ByteSourceJsonBootstrapper.java
+++ b/src/main/java/com/fasterxml/jackson/core/json/ByteSourceJsonBootstrapper.java
@@ -114,6 +114,10 @@ public ByteSourceJsonBootstrapper(IOContext ctxt, byte[] inputBuffer, int inputS
      * Method that should be called after constructing an instace.
      * It will figure out encoding that content uses, to allow
      * for instantiating a proper scanner object.
+     *
+     * @return {@link JsonEncoding} detected, if any; {@code JsonEncoding.UTF8} otherwise
+     *
+     * @throws IOException If read from underlying input source fails
      */
     public JsonEncoding detectEncoding() throws IOException
     {
@@ -178,7 +182,12 @@ public JsonEncoding detectEncoding() throws IOException
     /**
      * Helper method that may be called to see if given {@link DataInput}
      * has BOM marker, and if so, to skip it.
-     * @throws IOException 
+     *
+     * @param input DataInput to read content from
+     *
+     * @return Byte (as unsigned {@code int}) read after possible UTF-8 BOM
+     *
+     * @throws IOException If read from underlying input source fails
      *
      * @since 2.8
      */
@@ -272,6 +281,12 @@ public JsonParser constructParser(int parserFeatures, ObjectCodec codec,
      * ({@link com.fasterxml.jackson.core.json.ByteSourceJsonBootstrapper}); 
      * supports UTF-8, for example. But it should work, for now, and can
      * be improved as necessary.
+     *
+     * @param acc InputAccessor to use for accessing content to check
+     *
+     * @return Strength of match (never {@code null})
+     *
+     * @throws IOException if input access fails due to read problem
      */
     public static MatchStrength hasJSONFormat(InputAccessor acc) throws IOException
     {