diff --git a/base/count-same-value/README.md b/base/count-same-value/README.md
index 1a3e9899..33ca402b 100644
--- a/base/count-same-value/README.md
+++ b/base/count-same-value/README.md
@@ -51,6 +51,15 @@ var out = countSameValue( x, 1 );
 // returns 2
 ```
 
+In contrast to an implementation using the strict equality operator `===`, the function distinguishes between `+0` and `-0` and treats `NaNs` as the same value.
+
+```javascript
+var x = [ NaN, NaN, NaN ];
+
+var out = countSameValue( x, NaN );
+// returns 3
+```
+
 </section>
 
 <!-- /.usage -->
@@ -59,6 +68,10 @@ var out = countSameValue( x, 1 );
 
 <section class="notes">
 
+## Notes
+
+-   The function uses the [SameValue Algorithm][@stdlib/assert/is-same-value] as specified in ECMAScript 5.
+
 </section>
 
 <!-- /.notes -->
@@ -108,6 +121,8 @@ console.log( n );
 
 <section class="links">
 
+[@stdlib/assert/is-same-value]: https://github.com/stdlib-js/assert-is-same-value
+
 </section>
 
 <!-- /.links -->
diff --git a/base/count-same-value/docs/repl.txt b/base/count-same-value/docs/repl.txt
index 21681ab2..5fdd65f6 100644
--- a/base/count-same-value/docs/repl.txt
+++ b/base/count-same-value/docs/repl.txt
@@ -3,6 +3,8 @@
     Counts the number of elements in an array that are equal to a specified
     value.
 
+    The function treats `-0` and `+0` as distinct and `NaNs` as the same.
+
     Parameters
     ----------
     x: ArrayLikeObject
diff --git a/base/count-same-value/docs/types/index.d.ts b/base/count-same-value/docs/types/index.d.ts
index f83da7c0..24ccc5ab 100644
--- a/base/count-same-value/docs/types/index.d.ts
+++ b/base/count-same-value/docs/types/index.d.ts
@@ -25,6 +25,13 @@ import { Collection } from '@stdlib/types/array';
 /**
 * Counts the number of elements in an array that are equal to a specified value.
 *
+* ## Notes
+*
+* -   The function uses the [SameValue Algorithm][ecma-262-same-value-algorithm], as specified in ECMAScript 5.
+* -   In contrast to the strict equality operator `===`, `-0` and `+0` are distinguishable and `NaNs` are the same.
+*
+* [ecma-262-same-value-algorithm]: http://ecma-international.org/ecma-262/5.1/#sec-9.12
+*
 * @param x - input array
 * @param value - search value
 * @returns number of elements that are equal to a specified value
diff --git a/base/count-same-value/lib/main.js b/base/count-same-value/lib/main.js
index 7e3cbbfd..3be24e82 100644
--- a/base/count-same-value/lib/main.js
+++ b/base/count-same-value/lib/main.js
@@ -138,6 +138,13 @@ function complex( x, value ) {
 /**
 * Counts the number of elements in an array that are equal to a specified value.
 *
+* ## Notes
+*
+* -   The function uses the [SameValue Algorithm][ecma-262-same-value-algorithm], as specified in ECMAScript 5.
+* -   In contrast to the strict equality operator `===`, `-0` and `+0` are distinguishable and `NaNs` are the same.
+*
+* [ecma-262-same-value-algorithm]: http://ecma-international.org/ecma-262/5.1/#sec-9.12
+*
 * @param {Collection} x - input array
 * @param {*} value - search value
 * @returns {NonNegativeInteger} number of elements that are equal to a specified value