IBM Digital Analytics Cookies - Technical Appendix

This section describes technical implementation details for IBM® Digital Analytics cookies.

IBM Digital Analytics cookie logic does not interfere with the setting of existing non-Digital Analytics cookies. Prior to setting cookies, Digital Analytics checks to determine whether setting cookies would cause the maximum cookie length or number limit for the browser to be exceeded. In such cases, Digital Analytics libraries do not set additional cookies, preventing loss of other non-Digital Analytics cookies previously set under the domain.

The standard Digital Analytics cookies set for most implementations are as follows:

• Session cookies
  • 'Session' ID cookie and session-expiration cookie, where '99999999' is the assigned Digital Analytics Client ID). Expiration: at end of session.
  • New Sessions: Current browsers do not begin a new Digital Analytics ‘session’ when a new window or new tab is opened in the same browser. Browsers such as Safari running in iOS are exceptions to this rule and do start a new session with each new instance of the browser that is running in the device.
  • Session Inactivity Timeout: The default inactivity timeout for Digital Analytics 'session' cookies is 30 minutes. If no tags are received for a period of greater than 30 minutes, the next tag received associated with this session causes the session cookies to be reset and new session cookie(s) set. This and following tag data is associated with the new session.
    • 99999999_clogin (Client Managed) or 99999999_login (IBM Managed) - stores a numeric ten-digit ‘session ID’. The Client-Managed cookie additionally stores separate "e=" and "l=" subkey values, replacing the 99999999_expires cookie used by 'IBM Managed' implementations. The l= subkey value is the 10-digit 'session ID'. Set under the 'Cookie Domain' for 'Client Managed' implementations, or the 'Data Collection Domain' for IBM -Hosted implementations.
    • IBM Multisite: By default, the _clogin or _login session cookie contains the fully qualfied GlobalID|SiteID value: 59990000|SITEID-1_clogin/login and 59990000|SITEID-2_clogin/login. This results in separate sessions for each Site ID.
    • IBM Multisite Global ID Sessionization: To set a common session cookie across all Site IDs for a given Global ID, the following statement can be called to enable 'Global ID Sessionization' for Client Managed 1st party implementations:

      cmSetupOther({"cm_JSFEAMasterIDSessionCookie":true});

      To switch 'IBM Managed' implementations from the default Site-ID sessionization to Global ID sessionization, please submit a request to IBM Support.
    • 99999999_reset: IBM Managed 'Timeout' cookie timestamp value. Set under the ‘Data Collection Domain’ specified in parameter 3 of the cmSetClientID(...) call.
  • Utility Cookies: Expiration: at end of session.
    • cmTPSet: Used to determine when extra JavaScript-based technical properties data has been collected for the session. Set by eluminate.js 4.1.2 and later. Set under the 'Cookie Domain' value specified in parameter 4 of the cmSetClientID(...)call.
    • TestSess3: IBM Managed session cookie used to determine if the browser is accepting cookies. Cookie always contains the same value as the 'CoreID6' cookie described in the following section.
    • cmRS: 'Resend' cookie - used to persist automatically collected 'Link Click' data to destination pages. Not set until the visitor clicks on an instrumented link. Set under the 'Cookie Domain' (typically the 2nd level site domain). Discontinued and not set in eluminate.js 4.8.5H and later.
• Persistent cookie (1)
  • Set under the specified 'Cookie Domain' for 'Client Managed' implementations, or the 'Data Collection Domain' for 'IBM Managed' implementations.
    • CoreID6: Persistent cookie that stores a VisitorID value. Expiration: 15 years from date set. When set by Client Managed 1st party implementations, this cookie also includes one or more &ci=subkey values that specify the Client IDs to which this Visitor ID applies.
• Cookie Limit Setting
  • The cm_CookieLimit setting allows override of the default limit of "50" cookies per domain. This value indicates the maximum number of cookies allowed before the eluminate.js tag library will no longer attempt to set Digital Analytics cookies in a given domain. This limit prevents accidental roll-off of existing customer cookies.
  • The cm_CookieLimit variable should be set immediately after your cmSetClientID statement and prior to any cmCreate* tag function calls. This variable can be set by calling cmSetupOther(...):

    cmSetClientID("99999999",true,"data.coremetrics.com","site.com");
    cmSetupOther({"cm_CookieLimit":"80"});