What's this mysterious symbol used for the insert page break shortcut in Apple's Pages?
Solution 1:
According to the article Apple Mac OS X Keyboard Symbols, the symbol refers to the ENTER key.
And according to Apple, the shortcut keys to insert a Page Break is indeed:
Command + ENTER
or
Command + Return + Fn
As explained by Denis de Bernardy, Apple differentiates between the Enter key and the Return key, even if they are on the same physical location.
Solution 2:
Press 'command' and the 'fn' keys, then hit return. (I have no idea what the key is in the drop down menu, either!)