https://devzone.nordicsemi.com/f/nordic-q-a/28925/nfc-frame-details-understandingHi there, I&#39;m a beginner with NFC and there is somethings I don&#39;t understand with the NDEF Messages frames. I have a the PCA10040 Development Kit. I&#39;ve seen this schematic : blog.zenika.com/.../NFC_Record_Layout.png But I don&#39;t understand theen-USTelligent Community 13Fri, 05 Jan 2018 12:43:06 GMThttps://devzone.nordicsemi.com/thread/114456?ContentTypeID=1Fri, 05 Jan 2018 12:43:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3ffb0a5b-3af9-477d-83f7-d2e153cbc551JeanFifre<p>Okay thanks a lot for your reply, I hadn&#39;t read this documentation I guess I understood now !</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/114455?ContentTypeID=1Thu, 04 Jan 2018 11:00:16 GMT137ad170-7792-4731-bb38-c0d22fbe4515:17b914f8-6de9-45ef-8621-208ee6a5f0a2Michal<p>Hi, these bytes are set according to the NFC Forum &quot;Type 2 Tag Technical Specification&quot; Version 1.0 (section 4). Theres is however some freedom on how to set byte0 - byte9, all the details you can find in the nRF5 SDK documentation: <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v14.2.0/nfc_type2tag_format_dox.html">infocenter.nordicsemi.com/.../nfc_type2tag_format_dox.html</a> When it comes to NFCID1 (Serial number) length, by default, Type 2 Tag examples in the SDK use a 7-byte-long UID.</p><div style="clear:both;"></div>