Yup, thats the procedure for the classic (300-500). In the NG it is changed to
[737-700/800]
Use normal procedures and reference speeds unless a flaps 15 landing is planned.
If a flaps 15 landing will be made:
Set VREF 15
If any of the following conditions apply, set VREF ICE = VREF 15 + 10:
• engine anti–ice will be used during landing
• wing anti–ice has been used any time during the flight
• icing conditions were encountered during the flight and the landing temperature is below 10°C.
Since we do not operate the 900 our manuals only refer to 700/800, but i would think it is similar on the 900 as well.