How do tacos in private channels work?

The answer depends on which platform you're using.

Slack

Tacos given in private Slack channels are tracked and counted, but by default the message content doesn't appear on the activity feed or anyone's profile page — it stays private.

HeyTaco admins can change this. To update the setting, go to Admin → Settings and look for the Privacy section. Turning this on will make taco messages from private channels visible on the activity feed and profile pages going forward.

Microsoft Teams

Private channels in Microsoft Teams are not supported by HeyTaco — tacos given there won't be tracked. If you want to keep recognition within a smaller group, use a private team instead. Tacos work normally in channels within private teams.