  We introduce interpolation analogues of Schur Q-functions - the
multiparameter Schur Q-functions. We obtain for them several results: a
combinatorial formula, generating functions for one-row and two-rows functions,
vanishing and characterization properties, a Pieri-type formula, a Nimmo-type
formula (a relation of two Pfaffians), a Giambelli-Schur-type Pfaffian formula,
a determinantal formula for the transition coefficients between multiparameter
Schur Q-functions with different parameters. We write an explicit Pfaffian
expression for the dimension of skew shifted Young diagram. This paper is a
continuation of author's paper math.CO/0303169 and is a partial projective
analogue of the paper by A. Okounkov and G. Olshanski q-alg/9605042, and of the
paper by G. Olshanski, A. Regev and A. Vershik math.CO/0110077.
