Add caveat on partial dependence on the "cl" module, only available on
IRIX systems.
diff --git a/Doc/lib/libaifc.tex b/Doc/lib/libaifc.tex
index 76ff871..3b34b4a 100644
--- a/Doc/lib/libaifc.tex
+++ b/Doc/lib/libaifc.tex
@@ -13,6 +13,10 @@
\index{AIFF}
\index{AIFF-C}
+\strong{Caveat:} Some operations may only work under IRIX; these will
+raise \exception{ImportError} when attempting to import the
+\module{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 sampled. The number of channels indicate if the audio is