I recognize here (in this blog) that anytime someone in the DC community uses the term Father or Dad we seem to get all bent out of shape with definitions. I have fallen prey to this as well and I expect I will for some time to come. My DadBloggers post looks at it more from the social perspective as opposed to the biological although that is addressed.
In our world there seems to be a unwritten agreement that the term Dad is for the social father and Father is for the donor. I have generally written here and on the DC discussion groups under that construct and named myself that way as well. But somehow had I titled the DadBloggers post Daddying Children the dual definition I refer to would not have worked.