Question: After multiple output arrays are being utilized, how to select a specific one to be used as an RTL token for further use.

The array that RTL will use is the first array or fOut1

So if you have 3 arrays you typically work with in your calc and draw code, setup your indicator for 4 arrays and use the 1st array for your RTL result.

In the functoin CreateExtension, set your array count to 4...

/*****************************/
extern "C" cppExtension *CreateExtension(void)
/*****************************/
{
cppExtension *pExt= new myExtension();

pExt->setArrayCount(4);

And in your calc() function, you can declare the 4 arrays...

RTARRAY            output1(fOut1), output2(fOut2), output3(fOut3), output4(fOut4);

and whatever values you put in array output1 will be the RTL results.

And in functions such as parmsLoad, you can get the context with...

RTX_CONTEXT            ctx = getContext();

and then check for RTL context with...

if(ctx == RTX_CONTEXT_RTL)

and do things like show or hide controls based on this, or position controls based on this.  If you see the latest version of PivotStrategyAnalysis, I do exactly this.  And only show the RTL Result listbox in the RTL context as seen below...

In the PSA indicator, I actually have 14 arrays for the various data involved in maintaining the state of the PSA system.  Based on the selection the RTL Result listbox, I fill in the RTL array of fOut1 with the corresponding data (just moving the respective array over to array fOut1).  My rtlOutput array is the fOut1 array.