Board Thread:Support Requests - Designing Your Wiki/@comment-36541110-20200917142257/@comment-9605025-20200917162827

The Undertale Wiki uses AddRailModule to do that. However, that script only handles the insertion of content into the rail. The following features of that wiki's spoiler warning are implemented using custom JS that the wiki wrote itself.
 * 1) Message randomization
 * 2) Dismiss button and remembering that it was dismissed
 * 3) Inserted only for pages in certain namespaces
 * 4) Different language translations