SBZ Sowjetisch besetzte Zone. Soviet occupied zone. The name the GDR had, before it became GDR in 1949.
And on another note, while it was not necessarily compulsory to be a member of the Young Pioneers in the GDR, it entirely depend on local circumstances and it also changed fundamentally over time. Until 1954/55 a parallel education of Christian and Atheist youth indoctrination (aehem) took place. After that it was made "compulsory".
This gives a reasonable summary (in Engish)
Actually not reasonable, no, very good, (It quotes one of my favourite Professors....)
Including the Soviet Union itself? *Lunatic*, n. One whose delusions are out of fashion.
and those Zones were called ABZ, BBZ, FBZ and SBZ.
http://de.wikipedia.org/wiki/Besatzungszone
When the German states became 'independant states' in 1949 those names were 'officially' dropped, but not by some people...
And no, she only applied it to the GDR - interesting thought though.