Context: 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.

Question: What is usually dropped for the commercial naming of an HDTV product?
Answer: the frame rate

Question: What does 24p mean?
Answer: 24 progressive scan frames per second

Question: What does 50i mean?
Answer: 25 interlaced frames per second

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

Question: What is usually dropped for the commercial naming of an SDTV product?
Answer: Unanswerable

Question:  What does 54p mean?
Answer: Unanswerable

Question:  What does 10i mean?
Answer: Unanswerable

Question: When naming a commercial SDTV product, a frame rate can be specified without what?
Answer: Unanswerable