What does SDJ stand for?

Greensboro, NC - Location identifier - FAA (FAAL)

Sabrejets - NCIC boat manufacturer code (NCIC)

Sanada - Japan - Seismograph station code, US Geological Survey (SEIS)

Sendai - Japan - Airport symbol (OAG)

Senn d'Or - Vancouver Stock Exchange symbol

Society of the Devotees of Jerusalem (EA)

South Dakota Jaycees (EARSL)