@LB: To find out an post's "internal BBCode-like representation", this post has its own ID (The Report button uses this ID by calling in javascript: post(ID).report() like post529886.report() ).

Taken this ID, you can get its representation by going to:

http://www.cplusplus.com/forum/post.cgi?w=text&p= (ID here)

Example for my post:

http://www.cplusplus.com/forum/post.cgi?w=text&p=530030

You can see how you don't really need to "decode" a post via javascript.

This feature is available from the "Edit" button.

For those who go to this link:
[code]Also tags are rawly retrieved[/code]