read through twbs/bootstrap#21568

• Grid/Layout
  • Column offsets are gone (but will be back again in bootstrap v4 beta 2)
• Card
  • Renamed .card-block to .card-body Rename .card-block to .card-body twbs/bootstrap#22828
  • inverse is no longer a thing, just use .text-white (keep for convenience?)
  • Outline (.card-outeline-{color}) is now border util .border-{color}
  • Color (.card-{color}) is now bg util .bg-{color}
• Nav/NavBar
  • nav now has .nav-fill
  • nav vertical should accept a string for the responsive size (.flex-{size}-column)
  • nav now has .card-header-tabs/.card-header-pills (add boolean card prop?)
  • .navbar-inverse -> .navbar-dark
  • .navbar-toggler-left and .navbar-toggler-right have been removed
  • Navbar toggle class .navbar-toggleable{-sm|-md|-lg|-xl} -> .navbar-expand{-sm|-md|-lg|-xl}
• Popover
  • Renamed .popover-title to .popover-header and .popover-content to .popover-body Rename popover classes twbs/bootstrap#22829
  • tether -> poppers.js
• Tooltip
  • tether -> poppers.js
• Forms
  • form validations (feedback and "server-side" classes)
• Dropdowns
  • .show is now needed on .dropdown-menu when open
  • tether -> poppers.js
• Badge
  • .badge-default -> .badge-secondary

bootstrap v4 beta docs: https://getbootstrap.com/docs/4.0/getting-started/introduction/

The v5 branch will have the latest changes while the list is being completed. Items marked as completed on the list indicate that the item is addressed in the v5 branch. This issue will be closed one v5 has been merged into master.

Feel free to add anything not listed with a general description and link to either docs page or pr and I'll update the list 🙌