Gallery – can't format "Description"

that’s the part of my attachment-page that’s responsible for showing image description, which I put when adding a new media (I’m using standard wordpress gallery):
< ?php the_excerpt(); ?>
Well, it shows the description, but it ignores all formatting/html. I can’t put a link inside it, can’t bold font, nor even put a < br />! The formatting stays in description field after saving, it doesn’t reset or something. How I can make the “Description” to recognize basic html?
edit:
whatever.
Just change in loop-attachment.php the_excerpt to the_content.