131:9 Vidui must be recited standing but bent over, like one is for Modim. (If bending over is too difficult, one may bow his head; one may not lean on any object – Mishnah Brurah 607:10.) When mentioning each sin, one beats on his heart with his fist as if to say, “You’re the one who caused me to sin.” The order of the Vidui as written in the machzor is recited the same by everyone. If one knows he has committed a sin that is not mentioned in Vidui, it is appropriate for him to include that sin since the Vidui is recited quietly; he should confess his sin with a contrite heart and many tears. (If his sin is publicly known, he may even recite it out loud – MB 607:6.) Similarly, if his particular sin is mentioned in Vidui, then when he reaches it, he should feel more bitter about this one than the others. If one confessed about a particular sin on the previous Yom Kippur, even if one knows that he has not committed it again since, he can still repent for it again. This is praiseworthy as per Psalms 51:5, “…and my sin is ever before me.”
131:10 One does not recite “Avinu Malkeinu” after mincha on erev Yom Kippur, whether Yom Kippur falls on a weekday or on Shabbos.