I submitted a link, including some extra text. The submission failed, telling me that the extra text can only be 140 chars. That wasn't obvious, and it didn't tell me how much I missed by, so I didn't know how heavily I would have to edit what I'd put.

Edit: Now I see that it says there's a 140 char limit - I didn't see that first time round. It's part of the same contrast issue - really hard to see.

Edit: OK - you changed it. Thanks.