Can. 915 Those who have been excommunicated or interdicted after the imposition or declaration of the penalty and others obstinately persevering in manifest grave sin are not to be admitted to holy communion.
**[Canons 230 and 915
Withholding of Holy Communion by Extraordinary Minister](“http://www.canonlaw.info/canonlaw915.htm”)**
Under what conditions, if any, may extraordinary ministers withhold Holy Communion? (1) My roommate regularly lets her boyfriend spend the night with her in our apartment. I have objected to this behavior, and have been told to mind my own business. If she comes to me for Holy Communion on Sunday, must I give it to her knowing what I do about her conduct? (2) A prominent, pro-abortion Catholic politician belongs to our parish. I am very uncomfortable giving him Holy Communion. May I withhold it? (3) A man with an obscene tattoo came to me for Holy Communion. When I saw it, I told him to cover it up. He did, and I gave him Holy Communion. Later I wondered whether I had any right to say anything, but I also wondered whether I should have given Holy Communion to him knowing what I did about what was under his shirt sleeve. Can you advise?
Analysis of these three questions turns primarily on Canon 915 of the Code of Canon Law: “Those who have been excommunicated or interdicted after the imposition or declaration of the penalty and others obstinately persevering in manifest grave sin are not to be admitted to holy communion.” Nothing in this (or any other) canon exempts extraordinary ministers of Holy Communion from the duty incumbent upon all ministers of the Eucharist to protect the Blessed Sacrament from objectively scandalous or sacrilegious reception. Put another way, extraordinary ministers are responsible before ecclesiastical authority, and eventually before God, for their administration of Holy Communion. That said, however, extraordinary ministers are unlikely to know what canonists take for granted, namely, that Canon 915, even though it is a sacramental disciplinary norm and not penal law, requires a very careful reading for proper application. Huels, CLSA New Comm 1110-1111. We begin with an overview of the rights of the faithful in regard to the reception of the sacraments in general and the Eucharist in particular.
Canon 915 is drafted in a way that seems to assume that ministers of Holy Communion will have sufficient time and the information necessary to reach conclusions about administration of the sacrament. But sometimes, life is not  so cooperative; sudden, on-the-spot decisions might need to be made regarding one’s eligibility to receive Holy Communion. The most likely way this question will present itself is in regard to deportment or dress. For example, a neo-Nazi, in brown shirt with swastika armband, may appear one day in the Communion line; a woman dressed in a way that, according to prevailing social norms, seems intended to provoke sexual arousal in men, may present herself for the Eucharist; activists for causes at odds with Church teaching might wear distinctive garb or accouterments as a way to imply their right to Holy Communion despite their ecclesially contrarian stances. In each of these cases, it is likely (and indeed, it may even been intended) that a minister of Holy Communion will have little time to reflect on the situation and make an informed decision.
It would easy, and I think defensible, to fall back on the analysis offered above and conclude that a minister’s lack of certitude about, say, a subject’s degree of obstinacy justifies the administration of Holy Communion under such circumstances. But a good case can be made for exactly the opposite response as well. How so?
[RIGHT]Edward N. Peters, J.D., J.C.D.[/RIGHT]
Full citations: Edward Peters, Incrementa in Progressu 1983 Codicis Iuris Canonici: A Legislative History of the 1983 Code of Canon Law (Wilson & Lafleur, 2005); J. Beal, et al., eds., New Commentary on the Code of Canon Law (Paulist Press, 2000).