Parse variable names in a text added by a script in the same way as it done in a normal text.
For example, %%SEX%=%0%he%%%%SEX%=%1%she%% in a normal text is replaced by "he" or "she". It is very useful.
But if you add a text trough a script, it is not replaced. You can achieve the same effect with IF/THEN/ELSE, but it requires a lot more effort and cause severe code bloat if used in many sentences (for example, it's really kills scripted dialogs in my story).
I don't know for sure, but it's implementation will likely require adding only one call of an existing function.
It will benefit writers (including me), who will be able to make better scripts with less effort. Consequently, it will benefits readers, who will get more good stuff.