# Group theory notation used in physics (AdS/CFT)

This in the context of the AdS/CFT correspondence. I am reading this review on AdS/CFT Aharony et. al. (The MAGOO review) The abstract can be found here

Equation (2.50) of the above paper lists the $R$-symmetry groups of extended supersymmetries in $AdS_{p+2}$. He uses the following notation for the group:

$AdS_5: SU(2,2 | {\cal N}/2),~{\cal N}=2,4,6,8$

Can anyone explain this notation to me?