outbound STIR/SHAKEN and caller ID docs (#483)

Author: AdiSai

fern/calls/call-outbound.mdx

@@ -102,11 +102,129 @@ Use the [`example template`](/assets/batch-sample.csv) to get started.
 * Avoid blank rows or duplicated headers.
 * Double-check that your column names match the variables used in your assistant.
 
+## Trusted Calling and Caller ID
+
+To maximize call answer rates and establish trust with recipients, you should implement proper caller identification and trusted calling standards. This involves several key components that work together to verify your identity and build caller reputation.
+
+### STIR/SHAKEN Implementation
+
+**STIR/SHAKEN** (Secure Telephone Identity Revisited / Signature-based Handling of Asserted Information using toKENs) is a framework designed to combat robocalls and caller ID spoofing by digitally signing calls to verify the caller's identity.
+
+When you make outbound calls, STIR/SHAKEN provides three levels of attestation:
+
+- **Level A (Full Attestation)**: The service provider has verified both the caller's identity and their right to use the calling number
+- **Level B (Partial Attestation)**: The service provider has verified the caller's identity but not their right to use the number  
+- **Level C (Gateway Attestation)**: The service provider has authenticated the call source but cannot verify the caller's identity
+
+To enable STIR/SHAKEN on your Twilio numbers:
+
+1. **Complete Trust Hub verification** in your Twilio Console
+2. **Submit business information** including legal business name, address, and authorized representative details
+3. **Provide supporting documentation** such as business registration and tax identification
+4. **Wait for approval** - the verification process typically takes 5-7 business days
+
+<Note>
+STIR/SHAKEN is currently required for US and Canadian calling. Implementation helps ensure your calls are properly authenticated and less likely to be flagged as spam.
+</Note>
+
+Learn more: [Twilio STIR/SHAKEN Documentation](https://www.twilio.com/docs/voice/trusted-calling-with-shakenstir)
+
+### CNAM Registry Registration
+
+**CNAM** (Caller Name) displays your business name instead of just your phone number when you call someone. This significantly improves answer rates and establishes professional credibility.
+
+To register your business name with the CNAM database through your phone number provider:
+
+<Steps>
+  <Step title="Access CNAM registration">
+    Navigate to your phone number provider's CNAM registration portal (e.g., Twilio Console → Phone Numbers → Manage → Caller ID)
+  </Step>
+  
+  <Step title="Complete business profile">
+    Provide your complete business information:
+    - **Legal business name** (exactly as registered with your EIN)
+    - **Business address** and contact information
+    - **Business type** and industry classification
+    - **Tax identification number** or business registration details
+  </Step>
+  
+  <Step title="Designate authorized representative">
+    Assign a point of contact with authority to make changes:
+    - Full name and business title
+    - Direct phone number and email address
+    - Verification that they're authorized to represent the business
+  </Step>
+  
+  <Step title="Submit for verification">
+    Submit your application for review. Processing typically takes 3-5 business days, and you'll receive confirmation once approved.
+  </Step>
+</Steps>
+
+<Tip>
+Use an email address associated with your business domain rather than personal email addresses to expedite the approval process.
+</Tip>
+
+Learn more: [Twilio CNAM Branding Guide](https://www.twilio.com/docs/voice/brand-your-calls-using-cnam)
+
+### Caller Reputation Databases
+
+Beyond CNAM registration, registering with major caller reputation databases helps establish trust and reduces the likelihood of your calls being flagged as spam or blocked.
+
+#### First Orion Registration
+
+[First Orion](https://firstorion.com/) provides caller identification and spam protection services used by major carriers and call-blocking apps.
+
+**Registration benefits:**
+- Displays your business name and logo on supported devices
+- Reduces spam flagging and call blocking
+- Provides branded calling experience
+
+**Registration process:**
+1. Visit the First Orion business portal
+2. Verify your business ownership of the phone numbers
+3. Submit branding assets (logo, business description)
+4. Complete the verification process
+
+#### Hiya (Free Caller Registry)
+
+[Hiya](https://www.hiya.com/) operates one of the largest caller ID and spam protection networks, powering caller identification for millions of users.
+
+**Benefits of Hiya registration:**
+- Enhanced caller ID display across multiple platforms
+- Protection against false spam reporting
+- Access to call analytics and reputation monitoring
+
+**Registration steps:**
+1. Create a business account on Hiya's platform
+2. Verify ownership of your phone numbers
+3. Submit business profile and branding information
+4. Monitor your caller reputation through their dashboard
+
+### Best Practices for Trusted Calling
+
+<CardGroup cols={2}>
+  <Card title="Maintain consistency" icon="check">
+    Use the same business name across all registrations (CNAM, First Orion, Hiya) to avoid confusion
+  </Card>
+  <Card title="Monitor reputation" icon="chart-line">
+    Regularly check your caller reputation scores and address any spam reports promptly
+  </Card>
+  <Card title="Follow compliance" icon="shield">
+    Ensure all outbound calls comply with TCPA regulations and obtain proper consent before calling
+  </Card>
+  <Card title="Update information" icon="refresh">
+    Keep your business information current across all platforms when details change
+  </Card>
+</CardGroup>
+
+<Warning>
+Proper caller identification setup can take 2-4 weeks to fully propagate across all networks and databases. Plan accordingly when launching new outbound calling campaigns.
+</Warning>
 
 Note: Vapi free numbers have limited number of outbound calls per day. Import a number from Twilio, Vonage, or Telnyx to scale without limits.
 
 <Warning>
   It is a violation of FCC law to dial phone numbers without consent in an
-  automated manner. See [Telemarketing Sales
+  automated manner. See our [TCPA Consent Guide](/tcpa-consent) and the [Telemarketing Sales
   Rule](/glossary#telemarketing-sales-rule) to learn more.
 </Warning>