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+## nn_allocmsg
+
+Allocate message (compatible API).
+
+### Synopsis
+
+```c
+#include <nanomsg/nn.h>
+
+void *nn_allocmsg(size_t size, int type);
+```
+
+### Description
+
+The `nn_allocmsg` allocates a message structure of size _size_, and is primarily used to support zero-copy send operations, making use of the `NNG_MSG` special size indicator.
+The value returned is a pointer to the start of the message payload buffer.
+
+The value of _size_ must be positive, and small enough to hold reasonable message data plus book-keeping information.
+
+The value of _type_ *must* be zero.
+
+The returned message must be disposed of by either xref:nn_freemsg.adoc[`nn_freemsg`] or xref:nn_send.adoc[`nn_send`] when the caller is finished with it.
+
+### Return Values
+
+This function returns a pointer to message buffer space, or `NULL` on failure.
+
+### Errors
+
+[horizontal]
+`ENOMEM`:: Insufficient memory is available.
+`EINVAL`:: An invalid _size_ or _type_ was specified.
+`ETERM`:: The library is shutting down.
+
+### See Also
+
+xref:nn_errno.adoc[nn_errno],
+xref:nn_freemsg.adoc[nn_freemsg],
+xref:nn_reallocmsg.adoc[nn_reallocmsg],
+xref:nn_send.adoc[nn_send]