Three types of ranger ammo come to mind for the subsonic crowd, actually 4. I have shot all four. They would be:
147gr. 9mm SXT T-series @990fps
180gr. .40S&W SXT T-series @990 fps
230gr. .45GAP SXT T-series @830fps
230gr. .45ACP SXT T-series @ 830fps
Winchester marketed their first .40S&W 180gr. loads as Subsonic, these are the same rounds used by the CHP. I have a few old boxes of these in my ammo stores. All the newest stuff doesn't specifically state that it is subsonic, but WWB 180gr. is the exact same load, same specs, same velocity which would make it subsonic.
Subsonic was a marketing term in the early to mid-1990's for alot of JHP handgun ammo, started with the 147gr. 9mm stuff and proceeded to .40S&W when it first hit the market. Like another post stated, it was marketing as a result of infamous "Miami shootout" where a single 9mm 115gr. Silvertip was to blame by not reaching the heart, after going through an arm.