'NSS' NATO (JFC), Napoli Italy - STANAG-4285 - 8123.2 kHz

"NSS" is (most probably) the call-sign of the NATO "Allied Joint Force Command" (JFC) military transmitter in Napoli, Italy.
The transmission is produced in NATO's standard for HF communications, the STANAG-4285 (single-tone modem).
Most communications are encrypted, but some un-encrypted loops may be decoded with help of specialized software.
The "looped clear message", consists basically in the transmitter identification, followed by some text depicting code legends

8123.2 kHz USB/STANAG-4285
14-05-2017 UTC 13.09
Decoding free software: "SORCERER"

Monitoring location: Belgium, Grid: JO20sm
Radio: Elad FDM-DUOr
Antenna: Off-Center-Fed (OCF) Dipole Antenna 80-10 meters band
SDR Software: Elad FDM-SW2