Version 2.7 also has more robust moderation capabilities for server administrators and moderators, while accessibility, such as contrast for users with sight issues, has also been improved.[18] The ability for users to create and vote in polls, as well as a new invitation system to manage registrations have been integrated in April 2019.[19] Since the release of Mastodon 2.8.1 in May 2019, images with content warnings are, by default, blurred instead of completely hidden.[20] The most significant addition to Mastodon's functionality in June 2019 has been an optional single-column view in version 2.9.[21] This view is now displayed by default to all new users, although it can be changed to the original column-based view in Mastodon's preferences.