TDI as we all know is "Trader dynamic index" , developed by Dan Malone. This indicator is widely used in Market maker trading strategy . I have seen many variant of this script with different settings but in my indicator the settings are as per Market maker guidelines , so those who are using BTMM strategy can directly apply this on there chart and start trading . Those who don't trade BTMM but use TDI can alter there default setting form the menu and use as per there strategies.
One of the way in which i use it is , i use to find divergences at supply or demand preferably and then when price close below Market base line (Yellow) it gives me confirmation that trend is now shifted and then i will take my Buy or Sell trades .
I hope this indicator would be useful for you.