What's the coding for strikethrough text in this format?

[ParallelLines]

Prior thread:

Can we have all the active format tags in the UI

@codinghorror There are more tags that can be used. I discovered [u], which I think is a BB tag. < br> works as well so at least one html tag works. I realize the window for composing is small and the bar at the top cannot fit everything (a drop down?). If not doable, a list of working tags would be great. I have a dark theme and bold doesn’t show as … boldly as italic does. If there is a way to get [sup] and [sub] as well, that’d be great. Thanks in advance.

Additional page on formatting:

Forum ( discourse ) Text Formatting

(previously linked by @Joey_P in 2023)