Dear Eric,

There is no "dress code" for receiving Communion.  The requirements for receiving Communion under normal conditions include the Eucharistic fast, being a practicing Catholic and being in a state of grace.

Someone who is sinning cannot receive Communion, including if that person is causing someone else to sin which is in itself sinful.  Therefore someone cannot receive Communion wearing revealing clothing such as swimwear to Mass.

I agree that a transvestite could cause scandal and distraction, which might be enough to the point where sin is involved since our thoughts must be as focused as possible on Jesus a the moment of Communion rather than being distracted by who is wearing what.  Universally the Church has no strict dress code because different parts of the world consider different forms of dress to be appropriate and inappropriate.. therefore it would be up to the local bishop to determine what is proper.

If a parish priest is aware that someone is causing scandal and distraction he certainly could speak to the person involved to determine what's happening and develop a dress code for his own parish.

But until that happens, personally I would advise everyone in the pews to assume that this person is Catholic, has been to confession, and has fasted for an hour, and then not worry about him anymore unless he outwardly identifies himself as non-catholic.

Mr. Slavek