When using Special:InvestigateBlock to block both IPs and accounts in the same usage of the form, a warning should be displayed to the checkuser to avoid blocking them at the same time.
This is because https://foundation.wikimedia.org/wiki/Policy:Access_to_nonpublic_personal_data_policy places limits on when a checkuser can connect a specific IP address and an account. Because block logs are public, the usage of the form for both accounts and IPs creates the issue that the logs are performed at the same time and with the same reason.
As such, we should warn the user if they attempt to do this. We should still allow them for the use case of third-party wikis and because the IP may have already been disclosed (and therefore the use of the form doesn't break ANDP).
