superfields with a $B-L$ charge) with which to spontaneously break the $B-L$ symmetry. However, the $B-L$ anomaly cancellation conditions provide a subtle, and more minimal, alternative to this approach. Note that the three generations of right-handed neutrino superfields required to cancel these anomalies contain right-handed sneutrinos. Remarkably, the right-handed sneutrinos have the correct quantum numbers to spontaneously break $B-L$ in a phenomenologically acceptable way. Specifically, they are neutral under the SM, carry no baryon number and, of course, have a $B-L$ charge of one. Therefore, anomaly cancellation defines the most minimal $B-L$ extension of the MSSM. This model has exactly the MSSM particle content plus three generations of right-handed neutrino supermultiplets, and it does [*not*]{} require a new Higgs sector. This minimal $B-L$ theory was proposed in [@FileviezPerez:2008sx; @Barger:2008wn; @FP:2009gr; @Everett:2009vy], arguing for it’s appeal from a “bottom up” point of view.[^2] The same theory was found from a “top down” approach within the context of a class of vacua of heterotic $M$-theory [@Evans:1986ada; @Lukas:1998yy; @Braun:2005ux; @Braun:2005nv; @Braun:2006ae; @Ambroso:2009jd]. Due to the odd $B-L$ charge of the sneutrino, the minimal $B-L$ model must always spontaneously break $R$-parity. However, because the right-handed sneutrino has no baryon number, it’s vacuum expectation value 