If this policy is enabled, the preference is locked to true. If this policy is disabled, the preference is locked to false.
For a description of the preference, see:
https://github.com/mozilla/policy-templates/blob/master/README.md#preferences
| Registry Hive | HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER |
| Registry Path | Software\Policies\Mozilla\Firefox\Preferences |
| Value Name | dom.xmldocument.async.enabled |
| Value Type | REG_DWORD |
| Enabled Value | 1 |
| Disabled Value | 0 |