MUST be consistent for all consumers. For example,:c:expr:`PyBUF_SIMPLE | PyBUF_WRITABLE`

can be used to request a simple writable buffer.

..c:macro:: PyBUF_WRITEABLE

This is a:term:`soft deprecated` alias to:c:macro:`PyBUF_WRITABLE`.

..c:macro:: PyBUF_FORMAT

Controls the:c:member:`~Py_buffer.format` field. If set, this field MUST