Date last updated: October 2012

What are cookies and what are they used for?

Cookies are small text files that are stored by your web browser. They are primarily used to remember if you have visited a website before and to improve the way that sites work. For example, cookies can be used to:

  • remember information such as passwords so that you don't need to keep re-entering it;
  • personalise content by recording search and display choices such as layouts;
  • provide social network facilities;
  • record usage information to help us understand our users and ensure we are providing the right support.

There are different types of cookies, for example:

First party and third party cookies

First party cookies are set by the website you're visiting. They send data only to the servers for that domain, and the data cannot be altered or retrieved by any other website. If a user visits a website and a separate company sets a cookie through that website, this is a third party cookie. Examples of third party cookies are those set by social networks.

Session and persistent cookies

Cookies can expire at the end of a browser session or they can be stored for longer. Session cookies are not stored long-term; they are set when you visit a website, and expire as soon as the browser is closed.

Persistent cookies are stored on your device in between browser sessions and allow preferences to be remembered. They are used for a variety of reasons, including recording your preferred search results display.

To find out more about cookies, visit or All About Cookies.

Managing and deleting cookies

We use cookies to improve the way the site works and we don't gather any personally identifiable information. Blocking or deleting the cookies will impact on the way that the site works and you could lose some functionality, however you can control and manage cookies if you wish. You can visit for more information about how to control cookies on the major web browsers.

How Europe PMC plus uses cookies

Europe PMC plus uses cookies for three reasons:

  • To provide the login to Europe PMC plus;
  • For functionality;
  • To record general usage information.

Details about Europe PMC plus cookie use are given in the table below. You can selectively turn off some cookies, eg. Google analytics.
Note: if you stop Europe PMC plus using cookies completely then the service will no longer work for you.

Europe PMC plus use of Cookies

Cookies that are strictly necessary

We use cookies to allow you to sign in to Europe PMC plus, and these cookies are essential for you to use the service. If cookies aren't enabled on your computer, you will be unable to sign in.

Name Typical content Expires Purpose
NcbiLsSession_DUKMSS_loginlock Generated number When login process complete Session tracking.
NcbiLsSession_DUKMSS Generated number At end of session (when you exit browser) Session tracking.
NIHMS_SUPER_SESSION Generated code At end of session (when you exit browser) Session tracking.

Cookies for Functionality

Name Typical content Expires Purpose
NIHMS_LANG Language code At end of session (when you exit browser) Language setting.

Cookies for Measuring Website Usage (Google Analytics)

We use Google Analytics to analyse how our visitors use this website, in order to improve your experience on the site. Google Analytics uses only first-party cookies, which are available only to Europe PMC plus, and don't reveal any personally identifiable information.

Provider Name Typical content Expires
Google __utma Randomly generated number 2 years
Google __utmb Randomly generated number 30 minutes
Google __utmc Randomly generated number When you close your browser
Google __utmz Randomly generated number and information on how the site was reached (e.g. direct or via a link, organic search or paid search) 6 months

The Google Analytics privacy policy is available at:

The following is taken from the Google analytics Terms of Service:

This website uses Google Analytics, a web analytics service provided by Google, Inc. ("Google"). Google Analytics uses "cookies", which are text files placed on your computer, to help the website analyze how users use the site. The information generated by the cookie about your use of the website (including your IP address) will be transmitted to and stored by Google on servers in the United States . Google will use this information for the purpose of evaluating your use of the website, compiling reports on website activity for website operators and providing other services relating to website activity and internet usage. Google may also transfer this information to third parties where required to do so by law, or where such third parties process the information on Google's behalf. Google will not associate your IP address with any other data held by Google. You may refuse the use of cookies by selecting the appropriate settings on your browser, however please note that if you do this you may not be able to use the full functionality of this website. By using this website, you consent to the processing of data about you by Google in the manner and for the purposes set out above.

If you wish, you can opt out of being tracked by Google Analytics across all websites, see: