Captcha - ambiguous characters

Could the Captcha challenge be restricted to those characters which are not ambiguous? For example, could ohs (O) and zeros (0) be excluded? Similarly, could uppercase eye (I), lowercase ell (l), and the numeral one (1) be excluded?

I realise that the numeric character is unambiguous, but that’s only OK if you see a 1. However, if you see an ell, then you have no way of knowing whether it is a one or an eye.

I will look into this.

We updated the captcha with some instruction to help users identify the characters.  That will be about the best we can do.  I hope it helps.


I have a foolproof workaround. Copy and paste the Captcha text into the input box and delete the non-black characters.


That’ll work.  And it should be considered a solution.