Nodes and Chapter structuring

[Feloy]

Hello,

 I would like to know if a chapter structuring command
is always mandatory for each node. I can't find any
reference of this in the Texinfo 4.0 manual.

 This same Texinfo manual, for example, contains 4 nodes 
(table, menu location, updating commands, introducing lists)
for which the chapter struturing commands are only available
for Info files.

Thanks,

-
Philippe