BA02 stands for Budget Activity 02 - Exploratory Development
BA05 stands for Budget Activity 05 - Engineering and Manufacturing Development
BA01 stands for Budget Activity 01 - Basic Research
BA/RSP stands for Batting Average with Runners in Scoring Position (baseball)
BA/RRM stands for Biological Abstracts/Reports, Reviews, Meetings
BA/RD stands for Business Area Requirements Document
BA07 stands for Budget Activity 07 - Operational Systems Development
BA/PA stands for Budget Authorization/Program Authorization
BA/CA stands for Bone Age/Chronological Age Ratio
BA-NA stands for Biofeedback Association of North America (trade association; various locations)