TITLE: finite flat commutative group schemes arising from Abelian varieties
QUESTION [9 upvotes]: How are the finite flat group schemes $\mathcal{A}[\ell^n]$ arising from an Abelian scheme $\mathcal{A}/S$ singled out among other finite flat commutative group schemes of exponent $\ell^n$?

REPLY [3 votes]: I'm reminded of two papers by Maja Volkov, an erstwhile student of Jean-Marc Fontaine.  They are 
MR2148801 (2006a:14027) 
Volkov, Maja 
A class of $p$-adic Galois representations arising from abelian varieties over $\Bbb Q_p$.
Math. Ann.  331  (2005),  no. 4, 889–923. 
MR1837096 (2002d:11067) 
Volkov, Maja 
Les représentations $l$-adiques associées aux courbes elliptiques sur ${\Bbb Q}_p$. 
J. Reine Angew. Math. 535 (2001), 65–101.