1 Introduction

This fact sheet about Multistage Client & Visit Detection (MCVD) is designed to give you an
overview of this extension to SZM measurement in terms of identifying clients & visits for your site
(web, MEW (mobile-enabled website)). Exactly what the extension looks like, why it may be necessary and how activation will be
implemented in your site (web/MEW) will be described in more detail in the following chapters. Of course, if you still have any questions, feel free to contact our Customer Service team. Contact
details can be found on the last page of this fact sheet.

2 Multistage Client & Visit Detection (Web + MEW)

2.1 What does Multistage Client & Visit Detection mean?

Multistage Client & Visit Detection (hereinafter referred to as MCVD) is an extension of the SZM measurement process to optimise determination of Client and Visit performance indicators.

This add-on to SZM measurement determines clients and visits as accurately as possible, even in environments with low acceptance of 3rd-party cookies and weak data protection-related fingerprint features for the established hash method.

MCVD is a multi-stage process in which, in addition to the characteristics already described for determining clients and visits, a 1st party cookie can also be used to differentiate a client hash more accurately.

Here is an example of a 1st party cookie: „!bq0qb6“

If you have activated this option for your site, this 1st party cookie can be used when a client does not accept 3rd party cookies and recognition via a client hash in a special environment should only  be possible to a limited extent.

The method for detecting client and visitors is always selected based on its level of accuracy – site-independent detection via 3rd-party cookies still prevails. The fingerprint can be differentiated more accurately using the 1st-party cookie, so clients and visits can even be collected in more difficult environments.

2.2 Why is MCVD important?

As an experienced measuring service provider, we at INFOnline continuously monitor technical changes on the market. Of course, we specifically look at changes that have or could have a direct or indirect impact on the measurements collected via the SZMnG (new generation of scalable central measuring procedures).

In addition to the new data protection rules to comply with GDPR and technical changes in the market – e.g. in the mobile environment in some Safari browsers – particularly in preparation for upcoming browser updates (e.g. Firefox version 65), we have thus been prompted to also
implement advanced client and visit recognition. Collecting these important performance indicators capitalises on strong recognition features.

We therefore recommend that you activate MCVD on your site (web + MEW).

3 How do I activate MCVD?

3.1 How do I activate MCVD?

Activating MCVD as an extension to the existing client and visitor detection can be implemented by a minor adaptation of your integrated SZM tag. All you have to do is add the new parameter „sc“ (set cookie) in your tag. The MCVD process is activated by assigning the value “yes” to the “sc” parameter (see integration examples). This extension should be carried out across the site as much as possible. Once this has been done, an additional 1st party cookie will be set for clients visiting your site. MCVD is now activated on your site. Please note that activating MCVD will regularly set a 1st party cookie and send it to the measuring system. The transfer of 1st-party cookie information is independent of whether the 1st-party cookie is actually used for determining visits and clients within the MCVD procedure (see Section 2.1)

When activating MCVD by setting the new parameter „sc“, information on the 1st party cookie is forwarded to INFOnline as well as to further processing service providers and systems.

After initial activation for a client, MCVD is used across the domain.

Once a 1st party cookie has been registered for a site domain, the cookie information will be included in future requests for that domain.

In future, the „sc“ variable will be used for information transfer to the 1st party cookie. Please only use the parameter for information transfer to the 1st party cookie.


3.2 Note on MCVD activation in measuring system

3.2.1 MCVD activation for SZM measurement

After MCVD is activated for the measuring system by INFOnline on the 2nd January 2019, the additional 1st party cookie information can be used for determining clients & visitors. Assuming that MCVD is used on your site according to Section 2.1.

Possible effects of MCVD on visits and clients to your site are dependent on the site structure and individual usage patterns (for example, which browsers your site is accessed from) and are explained in the INFOnline tools (IDAS).


3.3 Integration examples

Parameters and variables for MCVD activation:

HEAD integration

<script> type="text/javascript" src=""></script>

BODY integration

<!-- OEWA VERSION="3.0" -->
<script type="text/javascript">
 if (window.iom) {
   var oewa_data = {
     "cn":"at", // country
     "st":"angebotskennung", // sitename
     "cp":"contentpath", // kategorienpfad
     "sv":"mo", // die Befragungseinladung wird im mobilen Format ausgespielt
     "ps":"lin", // Privacy setting
     "sc":"yes" // MCVD Aktivierung
<!--/OEWA -->

4 What else do I have to take into account when activating MCVD?

4.1 Please let us know!

In order to ensure that activating MCVD and the subsequent procedures goes as smoothly as possible, please tell us if you use MCVD on your site. Just send a short message with your site ID(s) to We are happy to assist with any queries.

4.2 Adapting the data protection declaration (DPD)

If you would like to use MCVD on your site, we recommend that you not only activate the extension in the tag, but also adapt your data protection declaration (DPD).

4.3 MCVD checklist for your site

  1. Notified ÖWA Customer Service about MCVD activation at
  2. Activated MCVD in ÖWA-Tag on entire site („sc“:“yes“)
  3. Adjustments made to your data protection declaration (DPD)