In a number of circumstances, the halachic status of מל ולא טבל ("circumcized but not immersed in a mikveh") takes on significance. For instance, regarding a nochri touching wine, the Shulchan Aruch ...
Rashi to B'reshis 12:5 quotes Rav Huna: "... whom they brought [to Judaism]. Avraham was converting the men and Sara the women...". My understanding is that nowadays female prospective converts study ...