I'm trying to create a complete list for my textbook, Anything Goes. One of the vocab words is "Ｂ超" which is translated as "ultrasound." I know there are other words in other textbooks that also contain roman characters, such as "Ｔ恤" meaning "T-shirt." How can I add such words to lists? Is it even possible?

I've asked about this before, and even the O for 零, but unfortunately at this time it is not possible. Basically, you have to live with incomplete lists, use the Chinese if there is a version without English, like 体恤, or just have the Chinese but make yourself a custom definition (which allows both English and Chinese) so you're reminded about the English bits. Hope that helps!

Another alternative is to use a flashcard program or even just actual flashcards to study stuff like that. Other examples would be Chinese numerical slang such as 88 (bye-bye), 38 (a nosy or sometimes an "uppity" woman), 2 (stupid), 250 (an idiot), 555 (crying or groaning), etc.

Perhaps if the Skritter team does introduce sentence study with a limited range of study options (i.e. no writing), stuff like this can be studied in that format.