Added req. details to ticket. If technical implications prohibit this fix, then error messaging should be clearer, e.g. "Your first tag has been saved as "crypto" and cannot be changed, please enter up to 4 tags" OR (if tags have been used in the post) "Your blog tags "yada" and "ya" count towards your 5 tags, please enter up to 3 tags." Then always show the number of available tags next to the tag box.