[NTG-context] disabling ligatures in selected words

Hi, in German typography, ligatures are disabled at boundaries between what used to be independent words (Wortfugen). Thusly, in a correct German text, you'd find Anflug (with fl-ligature) but Auf|lage (without ligature). I know that I can prevent a ligature with something like Auf\/lage or even Auf|*|lage. However, I typeset from xml and would much rather have a general solution so I can leave my generated xml files alone. Something like a list where I could list "ligature exceptions" the way we have a file with hyphenation exceptions. Is anything like this possible? Thanks Thomas