ShortCuts

OS X	Windows/Linux	Description
⌘+⌥+V	Ctrl+Win+V	Creates or pastes the contents of the clipboard as an inline link on selected text.
⌘+⌥+R	Ctrl+Win+R	Creates or pastes the contents of the clipboard as a reference link.
⌘+⇧+K	ShiftWinK	Creates or pastes the contents of the clipboard as an inline image on selected text.
⌘+⌥+B ⌘+⌥+I	Alt+B Alt+I	These are bound to bold and italic. They work both with and without selections. If there is no selection, they will just transform the word under the cursor. These keybindings will unbold/unitalicize selection if it is already bold/italic.
⌘+^+1…6	Ctrl+1…6	These will add the corresponding number of hashmarks for headlines. Works on blank lines and selected text in tandem with the above headline tools. If you select an entire existing headline, the current hashmarks will be removed and replaced with the header level you requested. This command respects the mde.match_header_hashes preference setting.
⌥+⇧+6	Alt+Shift+6	Inserts a footnote.