hidden-* vs visible-* đã bỏ và thay thế bằng.

• hidden-xs-down = d-none d-sm-block
• hidden-sm-down = d-none d-md-block
• hidden-md-down = d-none d-lg-block
• hidden-lg-down = d-none d-xl-block
• hidden-xl-down = d-none (same as hidden)
• hidden-xs-up = d-none (same as hidden)
• hidden-sm-up = d-sm-none
• hidden-md-up = d-md-none
• hidden-lg-up = d-lg-none
• hidden-xl-up = d-xl-none
• hidden-xs (only) = d-none d-sm-block (same as hidden-xs-down)
• hidden-sm (only) = d-block d-sm-none d-md-block
• hidden-md (only) = d-block d-md-none d-lg-block
• hidden-lg (only) = d-block d-lg-none d-xl-block
• hidden-xl (only) = d-block d-xl-none
• visible-xs (only) = d-block d-sm-none
• visible-sm (only) = d-none d-sm-block d-md-none
• visible-md (only) = d-none d-md-block d-lg-none
• visible-lg (only) = d-none d-lg-block d-xl-none
• visible-xl (only) = d-none d-xl-block