United States Census Abbreviations
A statistical study was done in 1923 on coal miners listed in the 1920 census. The codes used follow:
MH - coal miners who were also the heads of their households
BD - coal miners who were boarders in a household
BWF - coal miners who lived in their parent's household
USC - coal miners who were born in the United States
USW - coal miners who were born in the United States (don't know of any distinction between the w or the c)
1. Coal miners: As of 2004, information from Bill from Heritage Quest and Bethany Evans one of their professional census indexers.