# PetscCommGetNewTag

Gets a unique new tag from a PETSc communicator. All processors that share the communicator MUST call this routine EXACTLY the same number of times. This tag should only be used with the current objects communicator; do NOT use it with any other MPI communicator.

### Synopsis

    #include "petscsys.h"
    PetscErrorCode PETSC_DLLEXPORT PetscCommGetNewTag(MPI_Comm comm,PetscMPIInt *tag)

Collective on comm

### Input Parameter

comm -the PETSc communicator

### Output Parameter

tag -the new tag

### See Also

PetscObjectGetNewTag(), PetscCommDuplicate()

Level:developer
Location:src/sys/src/objects/tagm.c
Index of all Sys routines
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Index of all manual pages