* The user agent of the client.
This information is separated by spaces: "<code>sstClient: [YYYY][MM][DD]T[hh][mm][ss]Z" "IPv4 or IPv6" "User-Agent"</code>.
For example: <code>sstClient: 20210413T081027Z: 194.176.109.13 Mozilla/5.0 (X11; Linux x86_64; rv:85.0) Gecko/20100101 Firefox/85.0</code>.