Include accessibility bus as one of the well-known message bus
Submitted by Alejandro Piñeiro
Assigned to D-Bus Maintainers
From dbus documentation  you can read the following:
"The well-known type of the message bus. Currently known values are "system" and "session";"
But since the dbus based at-spi2 entered to replace the CORBA based at-spi, most of the linux systems are using a custom accessibility message bus. It is explained on at-spi2 README file  and on the (outdated) linux foundation wiki.
I think that it is worth to include accessibility as one of the well know message bus. Current situation is somewhat confusing if you start to look to the configuration file and what their options mean (for example, while reviewing ) and you find that on type, only session and system are supposed to be allowed.
Unless, at-spi2 is using wront that
<type>``</type> option. If so, any advice is welcome.
 http://dbus.freedesktop.org/doc/dbus-daemon.1.html  https://git.gnome.org/browse/at-spi2-core/tree/README#n93  http://www.linuxfoundation.org/collaborate/workgroups/accessibility/atk/at-spi/at-spi_on_d-bus#buslauncher  https://bugzilla.gnome.org/show_bug.cgi?id=722738