HMC615 R1 resistance

Hi 

I am FAE in Japanese distributor.

My customer is using HMC615LP4E in mass production.

Datasheet v03.0412 mentions "Note: Select R1 to achieve Icc by using equation below, R1 ≥ 18 Ohms."

He found the comment is nothing in the datasheet v01.0407.

Could you tell the background of the change? 

Please let me know If there is any problem other than larger ICC in  R1<18Ohms?

Best regards

N.Kokubo