In a map legend should the entries be singular or plural? It seems like they should be singular. i.e. Road instead of Roads. In my experience I have seen it both ways even on the same legend.
A Google image search for "map legend" lead me to conclude there is no consistent way of having a legend entry be singular or plural. The more authoritative maps I've seen have legend entries in singular. (USGS, National Geographic, etc)
So my question is, in what cases is a plural legend entry correct?
This guide says singular: http://gisgeography.com/map-elements-how-to-guide-map-making/ entry 32: Features in Legend are Present and Singular
This legend has legend categories in plural, but the individual entries are singular http://www.rootsweb.ancestry.com/~alfayett/Map_Legend.html