Don't have multiple notes with the exact same content. Then only the first instance will work. However, a labelnote and a normal note can work together even if they have the same content. But multiple labelnotes that are named the exact same with the exact same contents run into the same problem.
Overview and Purpose
Notes and their fancier cousins, labelnotes — let you add semi-hidden text. Instead of the note contents, readers see just a superscript "note" (or other label). To reveal the hidden text, simply click on the visible text.
Notes are useful to add tangential remarks, without cluttering up the main text. Those who arent interested can skip it easily. The more curious can find out what it says by clicking on it.
Please exercise good judgment when adding a note. Notes can be useful, but remember also that they can just as easily be abused. Too many notes on an article can easily result in Footnote Fever, which is to be avoided.
TV Tropes is awesome![[note]]Why? AwesomeDearBoy.[[/note]]
TV Tropes is awesome!note
Avoid overusing notes[[labelnote:why]]Because they can make an article hard to read.[[/labelnote]] on this wiki.
Avoid overusing noteswhy on this wiki.
The click-to-reveal function may not work when previewing an edit to a page. You just see the "note" text; clicking does nothing.
The wiki software inserts a space after the "note" text when rendered. However, it does not insert a space after the expanded text. So if the note is in the middle of a sentence, it will appear to have an extra space until expanded. Fortunately, it's barely noticeable, and even less so if the note is at the end of a sentence.
There is/was an old markup called a hottip. [[hottip:*:They look like this.]] They are no longer working properly — sometimes not appearing at all — and as such are being phased out. If you see a hottip on a wiki page, please either integrate the text into the article, or replace them with the note or labelnote markup, as appropriate.