 The application uses map tiles from a third-party (for example one of the mapping APIs) and adds its own collaboratively edited overlays to them, sometimes in a wiki fashion.If each user's revisions are contained in an overlay, the issue of revision control and cluttering can be mitigated.One example of this is the accessibility platform Accessadvisr, which utilises collaborative mapping to inform persons of accessibility issues, which is perceived to be as reliable and trustworthy as professional information.