Please take care when using parameters in tags. The terms of your Google Ad Manager contract prohibit passing any information to Google that we could use or recognize as personally identifiable information (PII). If you enter certain values into a field in Google Ad Manager, you may see a warning that reminds you that you must not use parameters to pass data that we would recognize as PII. Parameter friendly names that trigger this warning include, for example, email and username. Note that it is okay to use these friendly names if your purpose is not to collect information that Google could use or recognize as PII. (For example, a custom variable with the friendly name email and the value weekly is fine, but passing a user’s email address is not.) If we see any cause for concern, we may contact you to confirm that you are not using parameters in a way that is prohibited.
Learn more about our best practices to avoid sending PII.