If you're integrating with Salesforce or Zoho CRM, this article may not apply because you're most likely using GA Connector API-based integration.

This table shows the ID that each GA Connector field should have:

LabelInput IDLabelInput ID
All Traffic Sources all_traffic_sourcesLast Click Campaignlc_campaign
BrowserbrowserLast Click Channellc_channel
City (from IP address)cityLast Click Contentlc_content
Country (from IP address)countryLast Click Landing Pagelc_landing
First Click Campaignfc_campaignLast Click Mediumlc_medium
First Click Channelfc_channelLast Click Referrerlc_referrer
First Click Contentfc_contentLast Click Sourcelc_source
First Click Landing Pagefc_landingLast Click Termlc_term
First Click Medium fc_mediumLast Click Timestamplc_timestamp
First Click Referrerfc_referrerLongitudelongitude
First Click Sourcefc_sourceLatitudelatitude
First Click Termfc_termNumber of Website Visitspage_visits
First Click Timestampfc_timestampOperating SystemOS
Google Analytics CIDGA_Client_IDDevicedevice
Google Analytics Measurement IDGA_Measurement_IDRegionregion
Google Analytics Session IDGA_Session_IDPages Visited pages_visited_list
Google Click IdentifiergclidTime Spent on Website time_passed
IP Addressip_addressTime Zone time_zone