So in the end I chose a different strategy for banners that you may want to apply to your forum:
- Create a new topic dedicated to holding the banner. It can be in any category. I usually prefer using #staff.
- Tag the topic with #banner, so you can find them later.
- Either make a short post, or, my usual, create an image with pixel size 627x123 (this way, the scrollbars won’t be triggered and it will appear “clean” in most situations) ; and use that image as the anchor for a link to the topic or link you want to highlight, e.g.,:
[](/path/to/the/target/link)
This way you can keep a collection of banners that will stick to an acceptable format, without touching your existing topics.