Searching our forums
, you may discover that there already were some solutions suggested, but of the flimsy quality.
As I suggested few years ago, by now I am considering the only simple and good way to make a text not straight visible to the reader, making it the same color as background where it's published on. Using the mouse, then it will be possible to highlight this block of text, and when the text is highlighted, it appears visible in white color on blue background in most browsers. That way experienced forum readers may "open" a hidden text.
That's what my current free solution
is about. It's just an easy extension to provide yet another BB-code, similar to Quoting or Highlighting, and it is available in Compiler
Like to remind, this update comes in a series of plugins updates for miniBB 3
Have a nice Cosmonautics Day! :)