this is less a question and more a feedback concerning the AtlasUI Helper classes Overview.
(found here -> https://atlas.mendix.com/p/helpers/7881299347899271)
The list of classes is out of date, eg. there is no class .spacing-outer-none-right .
The actual class in Atlas is called .spacing-outer-right-none.
Also some are missing, ie. .display-ie8-only
Please update the list, as it is a nice "feature".
I gave feedback about this once and the matter about spacing-outer-none-right should've been fixed in the docs.
To bad. Work to do for Mendix ;-)
I agree this needs to be updated.