The Program Code defines the year, cycle, and program through a series of two-character codes that looks something like YPscNH19. These terms are used internationally.
You can learn about other AFS-USA acronyms and abbreviations here.
YP - Year program
SM - Semester Program
IP - Intensive programs (Summer, 4-8 weeks)
VS - Very short programs (Summer, 4 weeks or less)
ar - Arabic language study
bp - BP/AFS Global Citizens of Tomorrow
cb - Congress Bundestag Youth Exchange (CBYX) program
cc - Community College
cl - Culture Immersion Program
cs - Community service
fr - French language Study
fx - Future Leaders Exchange Program (aka FLEX)
gp - Global Prep
hs - Homestay
ja - Japan language study
ns - NSLI-Y program
sc - School program
so - Soccer program
sp - Spanish language study
ss - Green Summer School Hamburg, Germany
st - CRC Summer Program (6 weeks, school and bus trip)
ta - Teaching Assistant Program
tm - Team Mission (Ghana Summer Program)
xc - Green Camp (Bremen, Germany)
xe - Beginners Language and Culture (Karlsruhe, Germany)
xf - Intermediate/Advanced Language and Culture (Essen, Germany)
ys - Youth Exchange & Study (YES) program
NH = programs that start in the summer or fall (June-December - the same time of year as schools start in the Northern Hemisphere (NH)).
SH = programs that start in the winter or spring (January-May - the same time of year as schools start in the Southern Hemisphere (SH))
The final two digits of the Program Code indicates the year the program started.