No idea if this is possible for you guys to implement or not, but they've become a pretty common thing in other forums. Essentially, they hide information behind a button, so you don't have to scroll few a giant picture spam or wall of text if you don't need to. It also helps for referring to a particular post that was fairly long in the first place - quote it, spoiler it, and then reply. Anyone who is curious what you're specifically referring to can just click the spoiler tag and see what was initially said.
A visual example for those unfamiliar:
Different forum software and whatnot, but you can see a button to Show/Hide information within it. This specific image actually has a spoiler within a spoiler, but hopefully you can understand the basic idea.