The notion of a pomeron structure function arises in a model of electromagnetic diffractive scattering based on Regge factorization. Due to its small size we expect gluon recombination to occur significantly in the pomeron. The latest data from H1 (1999) show a Q(2) evolution in qualitative accordance with the GLR-MQ equations; these are the DGLAP (Altarelli-Parisi) equations corrected for the effect of gluon recombination.