[DOC] Extend intro/defn of 'transcoding' (#5602)

* Extend intro/defn of 'transcoding'

1 files changed, 8 insertions, 2 deletions

diff --git a/doc/encoding.rdoc b/doc/encoding.rdoc
index 490066b5df..fcbbf3afa5 100644
--- a/doc/encoding.rdoc
+++ b/doc/encoding.rdoc
@@ -274,8 +274,14 @@ followed by a colon, space and the Encoding name or alias:
 
 === Transcoding
 
-_Transcoding_ is the process of revising the content of a string or stream
-by changing its encoding.
+_Transcoding_ is the process of changing a sequence of characters
+from one encoding to another.
+
+As far as possible, the characters remain the same,
+but the bytes that represent them may change.
+
+The handling for characters that cannot be represented in the destination encoding
+may be specified by @Encoding+Options.
 
 ==== Transcoding a \String