NAIT RFID tags are not intended to be read visually. You may choose to use other visual panel tags to help with identifying your stock. You can also choose to purchase your NAIT tags as a birth set. These come with a matching visual panel tag, printed with the same information as the RFID tag.
If you are using a birth set, you do not need to link the panel tag to the RFID tag, because they have matching numbers.
If you are using other visual panel tags, you can link these to the animal's RFID tag in the NAIT system. To do this you will need to read the RFID tag once (either with a scanner or visually).