[[!FormIt? &validate=`color:required`]] ... <label>Color: [[!+fi.error.color]]</label> <input type="hidden" name="color[]" value="" /> <input type="checkbox" name="color[]" value="blue" [[!+fi.color:FormItIsChecked=`blue`]] > Blue <input type="checkbox" name="color[]" value="red" [[!+fi.color:FormItIsChecked=`red`]] > Red <input type="checkbox" name="color[]" value="green" [[!+fi.color:FormItIsChecked=`green`]] > Green
This question has been answered by krischel. See the first response.