I noticed that in some fonts two different lookups are used for discretionary ligatures. In some ones, a distinction is made between "Discretionary Legatures" at all and "Discretionary Legatures in Latin". But is it possible to somehow select if you want to use both, or only one of the two? For example, in LaTeX, if the <+dlig> characteristic is inserted, the lookups are also applied. Is there a method to choose, or to "number" these lookups, for example how can you do for stylistic sets, which are numbered? Thank you!