NFHS walks for 2018

[Tex]

The coach, pitcher or catcher of the defensive team may request an intentional walk either before or during the pitch count.
Rationale:This change to allow intentional walks was enacted to align fast pitch and slow pitch rules, to keep up with current trends of the sport, and also to maximize the flow of the game.

Question is: What is the limit, how often, conditions, etc. this intentional walk can be used. If no limits, a game would never end from all the walks (everybody walks).