Dress rules for inpatient therapy will be different from treatment center to therapy facility, and can be affected by the actual dependency receiving treatment. The bottom line is that the treatment facility will have the ultimate say as to what is or possibly is not acceptable or complies with their own unique rules.
A few examples of a dress code for an inpatient treatment facility can easily be found among the list of what not to bring. As an example, jeans may be permitted, but they might need to be plain as well as in good repair, without any rips and also cutouts.
With regards to swimwear, males most likely are not permitted to wear any kind other than boxer-style and females might be mandatory to wear one-piece swimwear that has some modesty to it. This might incorporate a responsibility to have shoulder straps, non-revealing cleavage lines as well as no high-cut legs.
Even something such as lingerie may fall under the dress code. It may be important for all addicts to use some form of underwear, including while exercising. Keeping undergarments hidden beneath apparel can also be aspect of the dress code for inpatient treatment.