In fact, it is the key member of a whole family of Graphic CEs, all with their own specific flags to indicate whether the answer is to be composed from last letters, middle letters, or other word fragments.
( ( In fact ) ( , ( it ( ( is ( ( the ( key member ) ) ( of ( ( a ( whole family ) ) ( of ( ( ( Graphic CEs ) , ) ( ( all ( with ( their ( own ( specific flags ) ) ) ) ) ( to ( indicate ( whether ( ( the answer ) ( is ( to ( be ( composed ( from ( ( ( ( ( ( last letters ) , ) ( middle letters ) ) , ) or ) ( other ( word fragments ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NN fact))) (, ,) (NP (PRP it)) (VP (VBZ is) (NP (NP (DT the) (JJ key) (NN member)) (PP (IN of) (NP (NP (DT a) (JJ whole) (NN family)) (PP (IN of) (NP (NP (NNP Graphic) (NNP CEs)) (, ,) (SBAR (WHNP (NP (DT all)) (PP (IN with) (NP (PRP$ their) (JJ own) (JJ specific) (NNS flags)))) (S (VP (TO to) (VP (VB indicate) (SBAR (IN whether) (S (NP (DT the) (NN answer)) (VP (VBZ is) (S (VP (TO to) (VP (VB be) (VP (VBN composed) (PP (IN from) (NP (NP (JJ last) (NNS letters)) (, ,) (NP (JJ middle) (NNS letters)) (, ,) (CC or) (NP (JJ other) (NN word) (NNS fragments))))))))))))))))))))) (. .)))
Key members of Graphic CEs have specific flags indicating whether answers are made from fragments, last letters, or middle letters. 
( ( ( Key members ) ( of ( Graphic CEs ) ) ) ( ( have ( ( specific flags ) ( indicating ( whether ( answers ( are ( made ( from ( ( ( ( ( fragments , ) ( last letters ) ) , ) or ) ( middle letters ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NN Key) (NNS members)) (PP (IN of) (NP (NNP Graphic) (NNP CEs)))) (VP (VBP have) (NP (NP (JJ specific) (NNS flags)) (VP (VBG indicating) (SBAR (IN whether) (S (NP (NNS answers)) (VP (VBP are) (VP (VBN made) (PP (IN from) (NP (NP (NNS fragments)) (, ,) (NP (JJ last) (NNS letters)) (, ,) (CC or) (NP (JJ middle) (NNS letters))))))))))) (. .)))