Split and join items

Split an item
While editing an item, place the cursor where you want to split it and press Ctrl/Cmd + Shift + Enter. The text before the cursor moves into a new item directly above; the text after the cursor stays in the original item.
The original item keeps its sub-items, along with any links, aliases and stars that point to it.
The new item gets the same format as the original — for example, a code item splits into two code items.
There must be text on both sides of the cursor. At the very start or end of an item, nothing happens.
Join items
Select two or more items on the same level (for example with Shift + ↑ or Shift + ↓) and press J. They are combined into one item.
The bottom item is kept. The text of the items above it is added in front of its text, each on its own line.
Sub-items of the other items move into the kept item, above its own sub-items.
The other items are deleted. Links and aliases that pointed to them stop working, just as when you delete an item.
Only items on the same level can be joined. Files, aliases and shared items can't be joined.