minor clarifications on producing transparent gifs

diff --git a/Imager.pm b/Imager.pm
index 8e81935f783410deca30b482ecc545afea7d7806..872e15039b23664e1f43418b4fc1ba647d60da1c 100644 (file)
--- a/Imager.pm
+++ b/Imager.pm
@@ -1583,7 +1583,9 @@ the previous value.
 =item gif_tran_color
 
 A reference to an Imager::Color object, which is the colour to use for
-the palette entry used to represent transparency in the palette.
+the palette entry used to represent transparency in the palette.  You
+need to set the transp option (see L<Quantization options>) for this
+value to be used.
 
 =item gif_positions
 
@@ -1641,6 +1643,9 @@ channel.
 
 =back
 
+This will only be used if the image has an alpha channel, and if there
+is space in the palette for a transparency colour.
+
 =item tr_threshold
 
 The highest alpha value at which a pixel will be made transparent when