The NDEF data is what is sent over NFC from an NFC enabled YubiKey. As the YubiKey has two programmable slots, you must choose which slot is used for NDEF; to set which slot is used, see Setting the NDEF Slot for NFC Usage. The following features are available over the NDEF interface of NFC enabled YubiKeys:
- Yubico OTP
- Static Password (Advanced Mode)
The YubiClip app from the Google Play Store can capture the output from an NFC enabled YubiKey over NFC, and allow it to be pasted into any field on an Android device.