  In [arXiv:1006.4939] the enumeration order reducibility is defined on natural
numbers. For a c.e. set A, [A] denoted the class of all subsets of natural
numbers which are co-order with A. In definition 5 we redefine co-ordering for
rational numbers. One of the main questions there, was: "For a specific c.e.
set A, consider set of all enumerations of it which is generated by some Turing
machine {TM_A} what are the associated order types in [A]?" Here, we propose
the same question for rational numbers, and we try to investigate the varieties
of c.e. sets on Q. The theories here are hold for R_c and we could repeat the
same theories in this domain, in a parallel way.
