The abbreviation HRS is used for High Resolution Spectrography, generally meaning using a Spectrograph with a Resolution on the order of 100,000 or higher, often aiming at Radial Velocity measurements.
The abbreviation is also used for such instruments, such as the Southern African Large Telescope (SALT)'s High Resolution Spectrograph or as part of the abbreviation for an instrument such as GHRS (the Goddard High Resolution Spectrograph) on HST.
The term Low Resolution Spectrography (LRS, Low Resolution Spectrograph) means the opposite, typically allowed to encompass any spectrography that is not HRS.
Radial Velocity (RV)
Southern African Large Telescope (SALT)