Does anyone know of any examples of the use of character counter on an input field?

I am working on a project that allows users to edit objects named by clicking on it using something similar to the HTML 5 Content-editable attribute.

Update:

  • The character limit is 30 not three.
  • Also the input field is meant to have the counter below it much like twitter has

However we need a way to notify the users of the 30 character limit to their object name. My first hypothesis is to use a text counter like the ones twitter uses.

Are there are some examples of other techniques that we can apply or does the method applied to a textarea field work best for an input as well?

Thanks,