Can I use
?

Content Security Policy 1.0

- CR

Mitigate cross-site scripting attacks by only allowing certain sources of script, style, and other resources.

Chrome

  1. 4 - 13: Not supported
  2. 14 - 24: Supported
  3. 25 - 123: Supported
  4. 124: Supported
  5. 125 - 127: Supported

Edge

  1. 12 - 122: Supported
  2. 123: Supported

Safari

  1. 3.1 - 5: Not supported
  2. 5.1: Partial support
  3. 6 - 6.1: Supported
  4. 7 - 17.3: Supported
  5. 17.4: Supported
  6. 17.5 - TP: Supported

Firefox

  1. 2 - 3.6: Not supported
  2. 4 - 22: Supported
  3. 23 - 124: Supported
  4. 125: Supported
  5. 126 - 128: Supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 108: Supported
  3. 109: Supported

IE

  1. 5.5 - 9: Not supported
  2. 10: Partial support
  3. 11: Partial support

Chrome for Android

  1. 123: Supported

Safari on iOS

  1. 3.2 - 4.3: Not supported
  2. 5: Partial support
  3. 6: Supported
  4. 7 - 17.3: Supported
  5. 17.4: Supported
  6. 17.5: Supported

Samsung Internet

  1. 4 - 23: Supported
  2. 24: Supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 80: Supported

UC Browser for Android

  1. 15.5: Supported

Android Browser

  1. 2.1 - 4.3: Not supported
  2. 4.4 - 4.4.4: Supported
  3. 123: Supported

Firefox for Android

  1. 124: Supported

QQ Browser

  1. 14.9: Supported

Baidu Browser

  1. 13.52: Supported

KaiOS Browser

  1. 2.5: Supported
  2. 3: Supported

The standard HTTP header is Content-Security-Policy which is used unless otherwise noted.

Resources:
CSP Examples & Quick Reference
MDN Web Docs - Content Security Policy
HTML5Rocks article