Consider renaming .radio and .checkbox

[cvrebert]

Perhaps to something like .radio-block, .checkbox-block?
Given Bootstrap's general CSS class naming scheme, the current names (.radio, .checkbox) could be misinterpreted as base classes for which the .radio-inline, .checkbox-inline would be modifier classes; but that's not how they work (.radio.radio-inline isn't currently a sensical combination).

[guylepage3]

+1 Makes sense.

[halfmage]

.radio is block by default; I think .radio-block would be unnecessary. But .radio-inline should have the same behavior like .radio except the display method (like you mentioned).

[mdo]

Coming in #19141.