Items that you have checked out (for example, when changing them) are locked by you and other users cannot edit these items. A red check mark identifies items that you have checked out. When you have finished editing an item, you can check it in to make it available for other users to edit. You can also check in all items at the same time by right-clicking the solution and selecting Check In All Files. Items checked out by other users are identified by a blue user icon. The Properties window displays the user that has checked out the items.
簡而言之，如果user A checkout了某個資源，則其他user無法再編輯該資源，直至user A checkin為止。
某個資源被checkout之後，在Cloud Application Studio裡會顯示一個紅色的小勾。
user完成編輯後，需點選check in 按鈕，這樣其他user才能繼續編輯。