Signage and overall educational displays regarding Eulemurs in zoos has only really been briefly touched upon in this thread so I've found some pictures in the gallery of signage in zoos that keep these lemurs.
Olmense zoo in Belgium, pretty impressive signage and in multiple languages
Zoo Parc Overloon in the Netherlands, pretty good in my opinion and again highlights conservation.
Zoo Parc Overloon in the Netherlands, again a good and succint sign in my opinion.
Domaine de Peschary zoo in France, not terrible but not great either, could be improved.
Palmyre zoo in France, quite interesting in that it includes a significant amount of information about the in-situ conservation of the Sclater's lemur.
Givskud Zoo in Denmark, not terrible but not great either could also be improved.
Planckendael zoo in Belgium, I quite like that the black lemur is given prominence over the ring tailed in this series of signs

.
Zoo Aquarium de Madrid in Spain, not keen on the amount of focus on the ring tailed lemur here considering that two other species are also kept and the font and graphics are a bit lacking too.
DierenPark Amersfoot zoo in the Netherlands, a different signage style and quite charming too despite the lack of information other than the name of species.
Burger's zoo in the Netherlands, an impressive little sign in multiple languages that really tries to educate the visitors and their misconceptions about the black lemur.
San Diego zoo in the USA, again I like how the Eulemur species signs are more prominent to the visitor than the ring tailed lemur.
Photo credits to
@KevinB,
@Maguari,
@Toddy,
@Maisie,
@vogelcommando,
@ThylacineAlive and
@timmychompchomp.