Since we can now notify people by quoting them in the edit summaries, it is now possible to exploit the fact that notification only require to point to a username using a link which content could be a space or an invisible char.
In the contrary to the notifications made "on page", notifications wikicode in the summary is not easily readable and it makes this trick less likely to be found.
This could be an issue and misused to hide notifications in an harassing or canvassing process for example.
- Notification using a space only ("[[User:AntonierCHF| ]]")
- Notification hidden in the summary using a space between "modification" and "presque" ("Ceci est un test de modification[[User:AntonierCHF| ]] presque invisible")
- Notification hidden in the summary using a space between "dummy" and "edit (english example)