diff --git a/base/set.jl b/base/set.jl
index d4ec130cd0c96..8b6abda5f9c75 100644
--- a/base/set.jl
+++ b/base/set.jl
@@ -104,6 +104,12 @@ const ⊆ = issubset
 ⊊(l::Set, r::Set) = <(l, r)
 ⊈(l::Set, r::Set) = !⊆(l, r)
 
+"""
+    unique(itr)
+
+Returns an array containing one value from `itr` for each unique value,
+as determined by `isequal`.
+"""
 function unique(C)
     out = Vector{eltype(C)}()
     seen = Set{eltype(C)}()
diff --git a/doc/stdlib/collections.rst b/doc/stdlib/collections.rst
index 034b449ac7116..81b1ba6cb3153 100644
--- a/doc/stdlib/collections.rst
+++ b/doc/stdlib/collections.rst
@@ -215,6 +215,12 @@ Iterable Collections
 
    Returns an array containing only the unique elements of the iterable ``itr``\ , in the order that the first of each set of equivalent elements originally appears. If ``dim`` is specified, returns unique regions of the array ``itr`` along ``dim``\ .
 
+.. function:: unique(itr)
+
+   .. Docstring generated from Julia source
+
+   Returns an array containing one value from ``itr`` for each unique value, as determined by ``isequal``\ .
+
 .. function:: unique(f, itr)
 
    .. Docstring generated from Julia source