This isn't an idea for the game, but for the forum. I placed it here since I thought it'd be the best section for it, but if it's in the wrong section, feel free to move it.
Basically the idea is to add strikeout text, and the BBcode tag associated with it. For those who don't know what strikeout text is, it's basically the tag [s][/s] where the text between the tags have a line running through in the middle, making the text between the tags crossed or 'struck' out. This was a thing in one of the previous forums we had, and it'd be nice if we could have it here.
Now before you say 'this is useless, barely anyone will use it so why should we have it,' kindly note the fact that the code, bold, italics, underline, and list tags are barely used as well, except in roughly 3-5 topics. This would be neat for crossing off certain things in a list for, say for example, a WIP map where a mapmaker would have a list of the things still in progress for said map or complete. Some people, such as myself, prefer crossing things out and it's virtually impossible without any way of doing so. There's also use for it outside of its intended purpose as well, such as crossing out something in your post and replacing it with something else for humor and whatnot.
I reckon admins can add this by using the custom BBcode feature and try to implement it in. I don't know how easy it is to add it in, but there's no harm in trying. I also don't know if strikeout text is already possible and if so, what the tags are. As you can see above, [s][/s] doesn't work so I assume it's not. The BBcode guide for phpBB also mentions nothing about this in their default tags list where they explain bold, italic, and underlined text.