LPTV stations may also choose a four-letter call sign with an -LP suffix (shared with low-power FM) for analog or -LD for digital; this is generally done only if the station originates programming. Class A television stations are assigned calls with -CA and -CD suffixes. Digital stations which use numbers receive a -D suffix, such as W42BD-D. All are despite the fact that most of the full-power digital television stations had their -DT (originally -HD) suffixes dropped by the FCC before -D and -LD were implemented. Digital LPTV stations have their digital RF channel numbers as part of their digital call sign, which may differ from the virtual channel (the analog number).