Parts that came with the bike, and serial numbers

OEM parts. You can mark a component as original equipment — Came with the bike (OEM). OEM parts add no "Installed" entry to your logbook on the day you add them, because you didn't install them; replacing one later still does. They carry an OEM badge on the public bike page, the components list filters by OEM only or OEM & upgrades, and you can mark a whole selection at once. Importing from a spec sheet or the catalogue onto a bike creates the parts as OEM, with a checkbox on the confirm step if that's not what you meant.

Serial numbers. Bikes take a frame serial number and components take their own. Both are private to your account and never shown publicly — they're there for an insurance claim or a police report, not for the bike page.