bpo-33283: Mention PNG as a supported format by Tcl/Tk. (GH-6479) (GH-6542)
(cherry picked from commit 4b685bf7192fff48c8effeeae4f4d64f9420ec0f)
Update only the documentation about image formats.
diff --git a/Doc/library/tkinter.rst b/Doc/library/tkinter.rst
index ce5e63a..7d80b40 100644
--- a/Doc/library/tkinter.rst
+++ b/Doc/library/tkinter.rst
@@ -801,12 +801,13 @@
Images
^^^^^^
-Bitmap/Pixelmap images can be created through the subclasses of
-:class:`Tkinter.Image`:
+Images of different formats can be created through the corresponding subclass
+of :class:`Tkinter.Image`:
-* :class:`BitmapImage` can be used for X11 bitmap data.
+* :class:`BitmapImage` for images in XBM format.
-* :class:`PhotoImage` can be used for GIF and PPM/PGM color bitmaps.
+* :class:`PhotoImage` for images in PGM, PPM, GIF and PNG formats. The latter
+ is supported starting with Tk 8.6.
Either type of image is created through either the ``file`` or the ``data``
option (other options are available as well).