reftex-part-resets-chapter

reftex-part-resets-chapter is a variable defined in `reftex-vars.el'.
Its value is

nil

Documentation:
Non-nil means, \part is like any other sectioning command.
This means, part numbers will be included in the numbering of chapters, and
chapter counters will be reset for each part.
When nil (the default), parts are special, do not reset the chapter counter
and also do not show up in chapter numbers.

You can customize this variable.