Thanks! If you feel like fixing it, here's the source for the doc file: https://github.com/bazelbuild/bazel/blob/master/site/docs/build-ref.html (Otherwise someone else will fix it later.)
Documentation does not list all attribute types
### Description of the problem / feature request:

https://docs.bazel.build/versions/master/build-ref.html#rules says:

> The full set of types that an attribute can have is: integer, label, list of labels, string, list of strings, output label, list of output labels

But there are quite a few more types that are available: https://docs.bazel.build/versions/master/skylark/lib/attr.html#modules.attr
site/docs/build-ref.html
site/docs/build-ref.html
diff --git a/site/docs/build-ref.html b/site/docs/build-ref.html
index 1b4d9ce3aa3562..944a692ff6bf0f 100644
--- a/site/docs/build-ref.html
+++ b/site/docs/build-ref.html
@@ -358,7 +358,7 @@ <h3 id="rules">Rules</h3>
   the <a href='be/overview.html'>Build
   Encyclopedia</a> for the full list of supported rules and their
   corresponding attributes.  Each attribute has a name and a
-  type.  The full set of types that an attribute can have is: integer,
+  type.  Some of the common types an attribute can have are integer,
   label, list of labels, string, list of strings, output label,
   list of output labels.  Not all attributes need to be specified in
   every rule.  Attributes thus form a dictionary from keys (names) to
