Android system NFC framework introduction and develop guide
TNF_EXTERNAL_TYPE
Given the following TNF_EXTERNAL_TYPE NDEF record, which is stored as the first record inside of an NdefMessage:
the intent filter would look like this:
Use TNF_EXTERNAL_TYPE for more generic NFC tag deployments to better support both Android-powered and non-Android-powered devices.
Note: URNs for TNF_EXTERNAL_TYPE have a canonical format of:
urn:nfc:ext::externalType, however the NFC Forum RTD
specification declares that the urn:nfc:ext: portion of the URN must be ommitted
from the NDEF record. So all you need to provide is the domain ( in the
example) and type (externalType in the example) separated by a colon. When
dispatching TNF_EXTERNAL_TYPE, Android converts the
urn:nfc:ext::externalType URN to a
vnd.android.nfc://ext/:externalType URI, which is what the
intent filter in the example declares.