I'm not sure what the proposed answer is. Not that anyone will care but not donating used (non-soiled etc.) textile is actually a violation of the law in a state like MA as I understand it.
For individuals though, it pretty much means you're supposed to take them down the street to a "donation" dumpster rather than toss them in the trash. Almost certainly, no one is going to come to your house and arrest you/fine you because they found an old t-shirt in your trash but they maybe could.
> Textiles means clothing, footwear, bedding, towels, curtains, fabric, and similar products, except for textiles that are contaminated with mold, bodily fluids, insects, oil, or hazardous substances.
Apparently it's also legal to jizz on your used clothing and then toss them in the garbage. ¯\_(ツ)_/¯ I don't make the rules!