Can someone tell me what tone this is?

[WSCB609]

Output Tone   023 DPL	023 DPL
Input Tone   023  DPL My ctcss setting does not go that low.	023 DPL

[nokones]

DPL 023 is not a CTCSS tone. CTCSS is an analog tone in hertz and DPL is a digital code. The lowest standard CTCSS freq (Continuous Tone-Coded Squelch System) is 67.0 Hertz (cycles). DPL (Digital Private Line) or  DCS (Digital Coded Squelch) lowest code is 023 and the highest code is 754. DCS/DPL may be either normal (D023N) or inverted (D023I)

They both function the same in protecting or keeping the receiver squelched until the tone or coded is present on the frequency/channel carrier. When the tone or code is interrupted by unkeying, the tone/code will cease thus the receiver will squelched and prevent other carriers without a tone or the incorrect code from opening up the receiver. Essentially it is a Nuisance Eliminator. Motorola trade name "Private Line" is misunderstood by many because no frequency is Private unless it is encrypted. Other radio manufacturers use a different name for their CTCSS/DCS or no name at all.