Shorthand object contsuction

I kept googling for the syntax but could never find it again.

// long: 
'{user: .user, title: .titles}'

// shorthand when key name matches original key name (user==.user)
'{user, title}'
// mix 
'{user, title_name: .title}'

From the man page:

You can use this to select particular fields of an object: if the input is an object with “user”, “title”, “id”, and “content” fields and you just want “user” and “title”, you can write
{user: .user, title: .title}
Because that is so common, there´s a shortcut syntax for it: {user, title}.

The long version allows to operate on they keys:

{id: .idx, metadata: .metadata.original_idx}