I'm wondering if there is a specification, white paper, etc. describing how to store a NDEF on a Mifare Classic tag?
I've been searching the forum, web etc. and didn't find anything (except how to store it on a NFC Forum Type 1/2/3/4 Tag).
I took me a long time to figure out that byte 9 of the Mifare Classsic Sector trailer has to be 0x40 if a Text NDEF is stored on it. Otherwise the Nokia 6212 says 'Tag can not be used.'.