Clarify that the API documentation is the public API.

1 files changed, 13 insertions, 0 deletions

diff --git a/docs/api/index.rst b/docs/api/index.rst
index 5935e216..d5fc013b 100644
--- a/docs/api/index.rst
+++ b/docs/api/index.rst
@@ -1,6 +1,19 @@
 API Reference
 =============
 
+These pages document the public API for ``cmd2``. If a method, class, function,
+attribute, or constant is not documented here, consider it private and subject
+to change. There are many classes, methods, functions, and constants in the
+source code which do not begin with an underscore but are not documented here.
+When looking at the source code for this library, you can not safely assume
+that because something doesn't start with an underscore, it is a public API.
+
+If a release of this library changes any of the items documented here, the
+version number will be incremented according to the `Semantic Version
+Specification <https://semver.org>`_.
+
+This documentation is for version |version| of ``cmd2``.
+
 .. toctree::
    :maxdepth: 1