diff --git a/ChangeLog b/ChangeLog
index 1c42fcfa11..9a7feef0e8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+Fri Apr 12 11:58:00 2013  Zachary Scott  <zachary@zacharyscott.net>
+
+	* array.c: Document synonymous methods, by windwiny [GH-277]
+	* bignum.c: ditto
+	* complex.c: ditto
+	* dir.c: ditto
+	* encoding.c: ditto
+	* enumerator.c: ditto
+	* numeric.c: ditto
+	* proc.c: ditto
+	* re.c: ditto
+	* string.c: ditto
+
 Thu Apr 11 23:41:46 2013  Tanaka Akira  <akr@fsij.org>
 
 	* common.mk: Add dependencies for include/ruby.h
diff --git a/array.c b/array.c
index 2646e904e7..0a2be58fcd 100644
--- a/array.c
+++ b/array.c
@@ -1320,6 +1320,9 @@ rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
+ *     ary.find_index(obj)             ->  int or nil
+ *     ary.find_index { |item| block } ->  int or nil
+ *     ary.find_index                  ->  Enumerator
  *     ary.index(obj)             ->  int or nil
  *     ary.index { |item| block } ->  int or nil
  *     ary.index                  ->  Enumerator
diff --git a/bignum.c b/bignum.c
index e709c21c52..6236ff32f7 100644
--- a/bignum.c
+++ b/bignum.c
@@ -3782,6 +3782,7 @@ rb_big_coerce(VALUE x, VALUE y)
 /*
  *  call-seq:
  *     big.abs -> aBignum
+ *     big.magnitude -> aBignum
  *
  *  Returns the absolute value of <i>big</i>.
  *
diff --git a/complex.c b/complex.c
index f6f63f6ebd..19c20b3565 100644
--- a/complex.c
+++ b/complex.c
@@ -2018,6 +2018,7 @@ numeric_arg(VALUE self)
 /*
  * call-seq:
  *    num.rect  ->  array
+ *    num.rectangular  ->  array
  *
  * Returns an array; [num, 0].
  */
diff --git a/dir.c b/dir.c
index a069bb34df..e4c53fd607 100644
--- a/dir.c
+++ b/dir.c
@@ -544,6 +544,7 @@ dir_inspect(VALUE dir)
 /*
  *  call-seq:
  *     dir.path -> string or nil
+ *     dir.to_path -> string or nil
  *
  *  Returns the path parameter passed to <em>dir</em>'s constructor.
  *
@@ -732,7 +733,7 @@ dir_seek(VALUE dir, VALUE pos)
 
 /*
  *  call-seq:
- *     dir.pos( integer ) -> integer
+ *     dir.pos = integer  -> integer
  *
  *  Synonym for <code>Dir#seek</code>, but returns the position
  *  parameter.
diff --git a/encoding.c b/encoding.c
index 0c92dfedef..3d89d52ea6 100644
--- a/encoding.c
+++ b/encoding.c
@@ -992,6 +992,7 @@ enc_inspect(VALUE self)
 /*
  * call-seq:
  *   enc.name -> string
+ *   enc.to_s -> string
  *
  * Returns the name of the encoding.
  *
diff --git a/enumerator.c b/enumerator.c
index 3aa0d2ea78..44c574728b 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -526,6 +526,8 @@ enumerator_with_object_i(VALUE val, VALUE memo, int argc, VALUE *argv)
 
 /*
  * call-seq:
+ *   e.each_with_object(obj) {|(*args), obj| ... }
+ *   e.each_with_object(obj)
  *   e.with_object(obj) {|(*args), obj| ... }
  *   e.with_object(obj)
  *
@@ -1501,6 +1503,7 @@ lazy_flat_map_func(VALUE val, VALUE m, int argc, VALUE *argv)
 
 /*
  *  call-seq:
+ *     lazy.collect_concat { |obj| block } -> a_lazy_enumerator
  *     lazy.flat_map       { |obj| block } -> a_lazy_enumerator
  *
  *  Returns a new lazy enumerator with the concatenated results of running
diff --git a/numeric.c b/numeric.c
index d142c67138..5e353da7c1 100644
--- a/numeric.c
+++ b/numeric.c
@@ -853,6 +853,7 @@ flo_div(VALUE x, VALUE y)
 
 /*
  *  call-seq:
+ *     float.fdiv(numeric)  ->  float
  *     float.quo(numeric)  ->  float
  *
  *  Returns float / numeric.
diff --git a/proc.c b/proc.c
index 4596003daf..9d083df269 100644
--- a/proc.c
+++ b/proc.c
@@ -1052,6 +1052,7 @@ mnew(VALUE klass, VALUE obj, ID id, VALUE mclass, int scope)
 
 /*
  * call-seq:
+ *   meth.eql?(other_meth)  -> true or false
  *   meth == other_meth  -> true or false
  *
  * Two method objects are equal if they are bound to the same
diff --git a/re.c b/re.c
index 16d7e3450c..fe7e3903b5 100644
--- a/re.c
+++ b/re.c
@@ -2643,6 +2643,7 @@ match_hash(VALUE match)
 /*
  * call-seq:
  *    mtch == mtch2   -> true or false
+ *    mtch.eql?(mtch2)   -> true or false
  *
  *  Equality---Two matchdata are equal if their target strings,
  *  patterns, and matched positions are identical.
diff --git a/string.c b/string.c
index 8b85739e70..d9a91b5a6f 100644
--- a/string.c
+++ b/string.c
@@ -8032,6 +8032,7 @@ sym_casecmp(VALUE sym, VALUE other)
 /*
  * call-seq:
  *   sym =~ obj   -> fixnum or nil
+ *   sym.match(obj)   -> fixnum or nil
  *
  * Returns <code>sym.to_s =~ obj</code>.
  */
@@ -8045,7 +8046,9 @@ sym_match(VALUE sym, VALUE other)
 /*
  * call-seq:
  *   sym[idx]      -> char
- *   sym[b, n]     -> char
+ *   sym[b, n]     -> string
+ *   sym.slice(idx)      -> char
+ *   sym.slice(b, n)     -> string
  *
  * Returns <code>sym.to_s[]</code>.
  */
@@ -8059,6 +8062,7 @@ sym_aref(int argc, VALUE *argv, VALUE sym)
 /*
  * call-seq:
  *   sym.length    -> integer
+ *   sym.size    -> integer
  *
  * Same as <code>sym.to_s.length</code>.
  */