Usually you can use it when you work with names of symbols (e. g. when you are searching in a symbol table).
These types of objects have their own GIDs: transitions, processes, process states, variables and channels.
GIDs are unique only for a particular type of object. E. g. there may exist a transition with the same GID as some variable, but there don't exist any two different transitions with the same GID.
These types of objects have their own LIDs: transitions, process states and variables.
LIDs are unique only for a particular type of object. E. g. there may exist a transition with the same GID as some variable declared in a same process, but there don't exist any two different transitions with the same LID in the same process. On the other hand in the different processes there may exist two trantitions with the same LID.
You can obtain this identifier by transition_t::get_partial_id() or you can use this identifier in functions process_t::get_transition(const sync_mode_t sync_mode,const std::size_t trans_nbr) and process_t::get_trans_count(const sync_mode_t sync_mode) .
Maybe you do not need such an identifier, but the generator of successors do.