# 6.2. Notification headers content

Additionally, the following parameters are included in the HTTP headers:

```
Content-Type: application/json; charset=UTF-8
X-Axepta-Signature: merchantid=6yt3gjtm9p7b8h9xsdqz;serviceid=63f574ed-d4ad-407e-9981-39ed7584a7b7;signature=20cdc8646eb268ea754842bdf0db1df21a2cf0b1c6e3e16e74ef7f7cca8f5450;alg=sha256
```

where:
* `merchantid` - client identifier,
* `serviceid` - store identifier,
* `signature` - notification signature,
* `alg` - hash algorithm (possible values: `sha256`).

> Verifying the notification signature is a critical part of authenticating the information transmitted in the notification package.