Definition for symbol not found when embedding swc

Question

When i embed the symbol "Tile" from swf, it works ok, when i try embedding the same symbol from swc, FlashDebugger throws this error:

Error: definition for symbol 'Tile' not found
[Embed(source="../lib/assets.swc", symbol="Tile", mimeType="application/x-shockwave-flash")]
Error: Unable to transcode ../lib/assets.swc.

Answer 1

1. Why use swc http://livedocs.adobe.com/flex/3/html/help.html?content=compilers_30.html
2. An example for importing swc file : Embedding/importing SWC at compile-time in ActionScript, without setting a library path
3. As per your comment on which one is better : Flex graphic assets: SWF or SWC?