Replace "Caveat" paragraphs by .. warning::s.
diff --git a/Doc/library/aifc.rst b/Doc/library/aifc.rst
index 0cfcb52..7f7d7fe 100644
--- a/Doc/library/aifc.rst
+++ b/Doc/library/aifc.rst
@@ -16,9 +16,10 @@
samples in a file. AIFF-C is a newer version of the format that includes the
ability to compress the audio data.
-**Caveat:** Some operations may only work under IRIX; these will raise
-:exc:`ImportError` when attempting to import the :mod:`cl` module, which is only
-available on IRIX.
+.. warning::
+
+ Some operations may only work under IRIX; these will raise :exc:`ImportError`
+ when attempting to import the :mod:`cl` module, which is only available on IRIX.
Audio files have a number of parameters that describe the audio data. The
sampling rate or frame rate is the number of times per second the sound is