A member reported that the 'strikethrough' BB code did not work for him. You can read about the pure HTML tag/code for this at
https://www.w3docs.com/learn-html/html-strike-tag.html
The following line should show the strikethrough BB code:
- First the code: [del]This is striketrhough'ed[/del]
- Now for real:
This is striketrhough'ed
For me with firefox on OpenBSD 7.1. it works correctly.
Before I start to mess around with the HTML code for this tag, please report whether this works for you. Please state your OS and browser(version)