Please answer a question about the following article about High-definition television:

For the commercial naming of a product, the frame rate is often dropped and is implied from context (e.g., a 1080i television set). A frame rate can also be specified without a resolution. For example, 24p means 24 progressive scan frames per second, and 50i means 25 interlaced frames per second.

When naming a commercial HDTV product, a frame rate can be specified without what?
a resolution