Regular nodes look like this:
<node> = <separator> File: <fn>, Node: <id1>, (Next: <id2>, )? (Prev: <id3>, )? Up: <id4> <general text, until the next ^_ or end-of-file>
At least one space or tab must be present after each colon and comma,
but any number of spaces are ignored. The <id> node identifiers have
following format:
<id> = (<lparen><infofile><rparen>)?<node-spec>? <node-spec> = <nodename> | <del><nodename><del> <del> = ^?
This <node> defines <id1> in file <fn>, which is typically
either ‘manualname’ or ‘manualname.info’. No parenthesized
<infofile> component may appear within <id1>.
Each of the identifiers after Next, Prev and Up
refer to nodes or anchors within a file. These pointers normally
refer within the same file, but ‘(dir)’ is often used to point to
the top-level dir file. If an <infofile> component is used then
the node name may be omitted, in which case the node identifier refers
to the ‘Top’ node within the referenced file.
The Next and Prev pointers are optional. The Up
pointer is technically also optional, although most likely this
indicates a mistake in the node structuring. Conventionally, the
nodes are arranged to form a tree, but this is not a requirement of
the format.
Node names containing periods, commas, colons or parentheses can confuse Info
readers. If it is necessary to refer to a node whose name contains any of
these, the <nodename> should be surrounded by a pair of DEL
characters (‘CTRL-?’, character number 127). makeinfo adds
these characters when needed in the default case. Note that not all Info
readers recognize this syntax. See Info Node Names Constraints.
The <general text> of the node can include the special constructs
described next.