In tonight's "Now" episode of The Walking Dead, Deanna wrote a certain message in Latin. Be warned, spoilers follow for those who haven't yet watched the episode.
During Deanna's writing the Alexandria map/blueprints, she wrote, "Dolor hic tibi proderit olim." A direct translation of this to English is, "This pain will be useful to you." Accompanying that final cryptic message was plans for the community, such as where to grow crops and what types to grow.
Sure seems as if Deanna is trying to prepare Rick or whoever will be in charge of Alexandria after her and assuming a terrible fate is not so distant.
The Walking Dead airs Sundays at 9 PM ET on AMC.