Posting a notice to identi.ca is easy. Simply type your text into the box below 'What's up, Fred'. As you are typing, notice the character count decrease at the bottom right. This indicates how many characters of the 140 available are left.
When you are finished, simply press 'Send'.
If your message exceeds 140 characters, identi.ca reports 'That's too long. Max notice size is 140 chars'. Your text remains so you can edit and trim to meet the limit.
If you reference a URL in your notice, two things can happen. If the length of the notice is less than 140 characters, the text is posted with the full URL.
Alternatively, if the URL causes the notice to exceed 140 characters, identi.ca will helpfully automatically shorten the URL using your configured URL shortening service.