Use of cookies on our sites

Information about the use of cookies on the IET websites.

Why are cookies used on the IET websites?

Often, websites need to maintain information as you move from page to page, and possibly between your browsing sessions. For example, you expect, when moving between pages in a web shop, that the site will keep track of the contents of your shopping basket. If you have logged in, you expect the site to recognise you on each subsequent page. Cookies are used to meet these expectations.

Cookies are small pieces of identifying information, stored by your browser on your PC, to enable such information about your session to be maintained. The cookie may contain actual information (e.g. the date of your last visit), or just a unique reference ID that allows the site to look up (for example) the contents of your shopping basket in its databases.

If a site sets cookies routinely, these can also be used to track your successive page views, and therefore your behaviour on the site, whether or not you are logged in. Unless you log in or complete an enquiry form, such use of cookies will not enable the site to identify you (because cookies can only give access to information that the site already has). The IET will not attempt to identify you unless you log in.

Cookies set by one site cannot be read by another. However, one web page may be made up of components (such as news stories, images or advertising), some of which are delivered from third parties. Each of those third-party sites will be able to set and read its own cookies on any page where its content appears.

How are cookies used on the IET websites?

The short version

If you block cookies from the IET websites, you will not be able to log in, and a range of other functions, such as the shopping basket and the tracking of new messages in the discussion forums, will fail. However, you will be able to browse most of the information on the IET sites. The IET uses some third-party services, and you may need to consult their policies separately.

The long version

The IET offers a range of websites and services to its members, customers and other web users, and these use cookies in varying ways. Therefore, if you block cookies, the effects will vary, depending on which IET service you are using. Many of the IET's cookies are essential to the delivery of the services that you have chosen: 

Cookie name Notes on uses



A single log-on works across most IET sites. These authorisation ("log-on") cookies simply contain session IDs, identifying you as an individual logged-on user. This avoids the need to send your user name and password every time that you request a page; therefore, the aim is enhanced security.

No personal information is stored in these cookies. If you choose not to use "Remember Me", the cookies are deleted when you log off from the IET sites, or close your browser. Please ensure that you accept all of these cookies if you wish to register and/or log on to the sites.



When you are not logged in, most IET sites use cookies to manage your session. You may block these if you wish, but some functions may not work fully; for example, you will not be able to page through results in the events calendar. The IET does not use these cookies to monitor your behaviour; they exist only to provide you with site functionality.

The book shop also uses your existing site cookies to keep track of the contents of your shopping basket, rather than setting additional ones. Without accepting cookies, you will not be able to use the shop.





In the discussion forums, there are further log-on cookies. The forums set other cookies, one for the last date you visited, and one for the latest posts you have seen. The aim is to be able to offer you quick access to the new postings when you next visit. These are permanent cookies. You can delete these additional cookies if you wish - it will just mean that the site cannot indicate new messages to you.


Determines the behaviour (shown or hidden) of the cookies alert above the global (search, login etc.) bar at the top of most IET web pages.


Determines the behaviour (shown or hidden) of the unsupported browser alert above the global (search, login etc.) bar at the top of most IET web pages.



The E&T Jobs site also uses supplementary cookies. Rejecting these cookies will mean that you are not recognised as logged on when visiting this site, even though log-ons work normally on other IET sites.



These are supplementary log-on cookies for Engineering Communities, similar to those above for E&T Jobs.



The Archives catalogue search uses cookies from to maintain your session and searches. If you block cookies, the Archives search will fail.

A second cookie records your preferred language for Archives searches.




The Career Manager professional development service uses cookies to store session information. The service may not work fully if you block these. There is specific information about cookies in Career Manager under the "legal" link on that site.



Manage access rights for the E&T Magazine site.


Cookies are used to track your information when you book a free place at a Local Network event. The booking will fail without the use of these cookies. The cookies come from


This cookie manages your session on the IET Digital Library. If you block cookies from that site, some functionality may not work reliably.

Cookies that you can block or reject without affecting your experience on the site:


and similar from

Site advertising servers are provided by AppNexus Open Adstream [new window]. Advertising mainly appears in specific sites, such as E&T Magazine and IET Electrical. Cookies are used, for example, to avoid showing you the same advertisement twice on different pages. They are delivered from a server in, so (as described above) they cannot be used to correlate your behaviour with your visits to non-IET sites.

Your use of the IET site will not be affected should you decide not to accept these "oax" advertising cookies.


The IET uses WebTrends. The values stored in WebTrends first party cookie are used for maintaining session and user identification across all your sub-domains. The cookie, set by WebTrends analytics service, used to track and report on visitor behaviour on a site for performance and improvement.

You can opt out WebTrends tracking for all sites, including the IET ones.





The IET uses Google Analytics. This service uses cookies [new window] to record and process information about your use of the sites (including your IP address) on behalf of the IET. The IET uses this information to evaluate visitors’ use of the sites and to compile statistical reports on site activity; the reports examine patterns of use rather than the behaviour of individual users.

You can opt out of Google Analytics [new window] tracking for all sites, including the IET ones.

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The IET was using Scout Analytics on some of its sites to help assess usage, interests and behaviour, but now no longer uses related first- and third-party cookies (which were generated from and from
It is possible that you still may have these from a previous visit to an IET website. You may block these without affecting your use of the site.


The IET uses web content quality tools from Siteimprove that help the IET identify areas of content that require correction or improvement. This could include spelling mistakes and broken links.
The 'CFDUID' cookie provides the IET with reports on the number of visitor attempts made to follow a link which turns out to be broken such that high volume link errors can be rectified quickly. These reports do not provide detail about the behaviour of individual users.
Your use of the IET site will not be affected should you decide not to accept these "CFDUID" cookies.

In addition, the IET uses third parties to deliver services to members and others. These third-party servers may set cookies in accordance with their own cookie and privacy policies, which you should consult separately. They include:

  • The IET uses email services from Adestra to inform its members and contacts of relevant activities, events, services and products. The levels of response to these emails are tracked, in order to improve the effectiveness of IET communications. Since emails are sent from addresses in the domain, and should you click on links in such emails, you may find cookies from that domain.
  •, which uses Stream UK to deliver webcasts. These appear mostly in the site, but also embedded in some web pages elsewhere. You may block cookies from if you wish.
  • The electronic information services provided to members by the IET Library.
  • Some pages, especially in E&T Magazine, include content from Twitter, YouTube, Flickr and other services. These have their own cookie and privacy policies.
  • The AddThis social bookmarking and sharing widget appears on some pages, especially again in E&T Magazine. Its privacy policy is accessible by hovering over the widget.
  • If the IET is currently conducting a survey or requesting feedback (for example in user trials), cookies may be used to record the fact that you have seen the invitation to respond. The aim is to avoid showing you the invitation repeatedly. If you reject these cookies, you may see the message a number of times.

Using your browser to block cookies, and further information

The site AllAboutCookies [new window] provides independent information on cookies, and how to block them in specific browsers.

If you have questions about our use of cookies, please contact

Updated 1 December 2017