[luatex] managing user_defined whatsit nodes

[Stephan Hennig]

Hi,

user-defined whatsit nodes (see sec. 8.1.4.25 in luatexref-t.pdf) are an
alternative to attributes for storing information in a node list.  But
how does a user (package writer) tell between his user-defined whatsit
nodes and third party user-defined whatsit nodes?  Is there a way to
allocate at run-time a unique identifier to mark nodes, similar to the
attribute allocation mechanism provided by package luatexbase?

Best regards,
Stephan Hennig