<?php
class Kwf_Validate_NoTags extends Zend_Validate_Abstract
{
    const INVALID_TAGS = 'invalidTags';

    public function __construct()
    {
        $this->_messageTemplates[self::INVALID_TAGS] = trlKwfStatic("Must not include tags");
    }

    public function isValid($value)
    {
        if (strip_tags($value) != $value || stripos($value, 'Content-Type:') !== false) {
            $this->_error(self::INVALID_TAGS);
            return false;
        }
        return true;
    }
}

<?php
class Kwf_Validate_NoTags extends Zend_Validate_Abstract
{
    const INVALID_TAGS = 'invalidTags';

    public function __construct()
    {
        $this->_messageTemplates[self::INVALID_TAGS] = trlKwfStatic("Must not include tags");
    }

    public function isValid($value)
    {
        if (!$value) return true;
        if (!is_array($value)) {
            $value = array($value);
        }
        foreach ($value as $key => $val) {
            if (strip_tags($val) != $val || stripos($val, 'Content-Type:') !== false) {
                $this->_error(self::INVALID_TAGS);
                return false;
            }
        }
        return true;
    }
}

Fix problems with validating null and integer values for tags
Fix problems with validating null and integer values for tags
