Both: the blogpost Must be a question.

— t_sharpQ is for well-defined, short-n-sharp (jolt) often yes/no questions

— t_stickyQ is for non-trivial questions to be reviewed periodically due to real risk of crowding out.

Reality — Mental energy is limited. You can’t focus on many things for a long time.

— T_fertile overlaps with stickyQ, when the question is important, and not yet fully explored.