A quote from Feather Brain (2013, Stackpole Books) by Drew Chicone:
"UV reflective materials do not react under a UV light. This means that particles of light in the UV specturm that hit the material will be reflected and become more visible to predators that can see UV light. If no light is present, then there is no UV light either. If there is no UV light, then there is no UV reflection form the materials.
If birds, fish, and insects can see UV light, and humans cannot, materials that claim to be UV reflective cannot be tested with a blue light or a UV light since they simply reflect UV light, which we cannot see.
Most, but not all, feathers are UV reflective. Some feathers reflect more UV light than others, such as jungle cock, peacock, and iridescent exotic bird feathers. However, birds in the ostrich family, owls, and hummingbirds have no UV reflective feathers at all...
White or lighter colored feathers are highly UV reflective, while darker or black feathers reflect far less UV light. White has the highest UV reflectivity, followed by blue, yellow, green, red, brown, and then black. Highly reflective UV colors like fluorescents are not typically found in nature, but they work well to get the attention of fish.
So what are you seeing when materials light up in the dark when you shine a UV light on them? These are UV reactive materials. UV reactive materials shine, radiate, incandesce, or fluoresce when you hit them with a UV light. Typically, this means that they have been dyed with UV reactive dyes..." (pp. 11-13).
I recommend the book. And I wouldn't be surprised that UV reflective materials were not advertised as such. They simply reflect more light, and UV light is part of that spectrum. It's not a perfect parallel, but it's akin to how most shirts do not advertise their UPF rating, but those marketed toward comfort in the sun or "performance wear" boast UPFs in the normal range.