Google Analytics 4does not accept custom eventnames that include spaces. Segmentreplaces spaces in the Event Name intheCustom Event action with an underscore. As a result, you will see custom events snake cased in Google Analytics 4.

Google Analytics 4has strict rules for eventnaming and requires you to adhere to those requirements in order to successfully send events. Segmentwill replace all spaces with underscores to ensuretheevent name adheres to Google's[event naming rules](https://support.google.com/analytics/answer/13316687?hl=en&ref_topic=13367860&sjid=2167389739796023681-NA#zippy=%2Cweb){:target="_blank"}. As a result, you will see custom events snake cased in Google Analytics 4.

Event names are case-sensitive in Google Analytics 4. If you would like all event names to be lowercase, use the**Lowercase Event Name** setting when you create a Custom Event mapping and select`Yes` from the dropdown. If this setting is set to`No` (`false`), Google treats event names with different casing as distinct events. For more information, see[Google Analytics 4 Event name rules](https://support.google.com/analytics/answer/13316687?hl=en&ref_topic=13367860&sjid=2167389739796023681-NA#zippy=%2Cweb){:target="_blank"}.

Event names are case-sensitive in Google Analytics 4. If you would like all event names to be lowercase, use the**Lowercase Event Name** setting when you create a Custom Event mapping and select`Yes` from the dropdown. If this setting is disabled, Google will treat event names with different casing as distinct events.

Keep in mind that custom events will not appear in Google's standard reports; you will need to set up custom reports for meaningful analysis.