One dialect construct found in a document.
The callout class, or an empty string for another kind.
The map caption, or an empty string for another kind.
The link destination read by commonmark, or an empty string for another kind.
The construct kind: callout, map, unreadable, or link.
callout
map
unreadable
link
The latitude exactly as written, or an empty string for another kind.
The longitude exactly as written, or an empty string for another kind.
The recognised node-reference scheme, or an empty string when none applies.
Reader-visible or source-preserving text carried by the construct.