Tweak wording

docs/developing.rst

@@ -776,9 +776,17 @@ memory shared by an SPOSet and all of its clones.
 Log and error output
 ~~~~~~~~~~~~~~~~~~~~
 
-``app_log``, ``app_warning``, ``app_err`` and ``app_debug`` print out messages only on rank 0 to avoid repetitive message from every MPI rank. For this reason, they are only suitable for outputing messages identical to all MPI ranks. ``app_debug`` prints only when ``--verbosity=debug`` command line option is used. Messages that come out from one or a few MPI ranks should use ``std::cout`` and ``std::cerr``.
-
-If the code needs to be stopped after an unrecoverable error, a bad input for example, that happens uniformly on all the MPI ranks, avoid using ``app_err`` together with ``Communicate::abort(msg)`` or ``APP_ABORT(msg)`` because any MPI rank other than rank 0 may force stop the whole run before rank 0 gets a chance to print out the error message. To secure the printout before stopping, use ``Communicate::barrier_and_abort(msg)`` if an MPI communicator is avaiable or throw a custom exception ``UniformCommunicateError`` and capture it where ``Communicate::barrier_and_abort()`` can be used. Note that ``UniformCommunicateError`` can only be used for uniform error, improper use may cause QMCPACK hanging.
+``app_log``, ``app_warning``, ``app_err`` and ``app_debug`` print out messages only on rank 0 to avoid repetitive messages from
+every MPI rank. For this reason, they are only suitable for outputing messages identical to all MPI ranks. ``app_debug`` prints only
+when ``--verbosity=debug`` command line option is used. Messages that come from only one or a few MPI ranks should use ``std::cout``
+and ``std::cerr``.
+
+If the code needs to be stopped after an unrecoverable error that happens uniformly on all the MPI ranks, a bad input for example,
+avoid using ``app_err`` together with ``Communicate::abort(msg)`` or ``APP_ABORT(msg)`` because any MPI rank other than rank 0 may
+stop the whole run before rank 0 is able to print out the error message. To secure the printout before stopping, use
+``Communicate::barrier_and_abort(msg)`` if an MPI communicator is available or throw a custom exception ``UniformCommunicateError``
+and capture it where ``Communicate::barrier_and_abort()`` can be used. Note that ``UniformCommunicateError`` can only be used for
+uniform error, improper use may cause QMCPACK hanging.
 
 In addition, avoid directly calling C function ``abort()``, ``exit()`` and ``MPI_Abort()`` for stopping the code.