[NTG-context] Question on "back" key in \blank

Dear list, Sorry if question is trivial but I’d like to use « back » key in \blank to discard a \blank just before. The following MWE illustrates : \starttext Title. \blank[none] \blank[back, -line] %% I’d expect this one to discard the \blank[none] (as if it was not present) \startalignment[broad, flushright, hanging]Right.\stopalignment \stoptext I’d expect that Title and Right words to be on the same line, but they are not. Did I misunderstood the meaning of ‘back’ key ? Thanks a lot for help and time, Best regards Joseph Canedo