title: Can I program an RFID tag to present natively-actionable data to a smartphone (such as a URL), alongside other custom data?
body: <p>I've learned that the NFC tag spec offers a few standardized formats (plain text, e-mail, Wi-Fi SSID, business card data, URL, etc.) that compatible phones are capable of natively responding to simply by enabling NFC functionality in OS settings.</p>
  
  <p>Am I correct in understanding that no 3rd-party app installation is needed for this to function? Does this invariant hold true for both Android and iOS 11+? I see that iPhone 7 and up supports Core NFC.</p>
  
  <p><strong>If the above is true</strong>, my actual question follows.</p>
  
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  <p>I have an application to display some data from an RFID chip that would be deployed with moderate ubiquity.</p>
  
  <p>Under normal circumstances, a dedicated app would be used to fetch and display this data, to guarantee consistency (everything's always in the same place) along with presentational clarity.</p>
  
  <p>However, in rare situations, the devices (phones) scanning the RFID tags may not have the reader app installed. They may also not have any cellular connectivity, making app installation difficult. (This is a rare/unlikely but plausible edge-case.)</p>
  
  <p>In such a scenario, would it be possible for the tag to deliver a "natively-actionable" piece of information to the phone, such as a plaintext fragment of data, similar to how NFC tags work?</p>
  
  <p>It would be great if I could offer a URL and also a text fragment. <a href="https://stackoverflow.com/questions/19402435/two-actions-on-one-nfc-tag">Two actions on one NFC tag</a> suggests this <em>may</em> be doable but it sounds like it's a hack exploiting undefined behavior (?).</p>
  
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  <p>The RFID tag itself does not need much onboard capacity; the maximum capability required would be retrieving a few hundred bytes of data that is occasionally overwritten. Some read and write counters would probably be the only other feature required.</p>