2 files changed, 93 insertions, 0 deletions
diff --git a/docs/reference/src/api/util/nng_random.md b/docs/reference/src/api/util/nng_random.md
new file mode 100644
index 00000000..3f8ac39e
--- /dev/null
+++ b/docs/reference/src/api/util/nng_random.md
@@ -0,0 +1,45 @@
+= nng_random(3supp)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_random - get random number
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+#include <nng/supplemental/util/platform.h>
+
+uint32_t nng_random(void);
+----
+
+== DESCRIPTION
+
+The `nng_random()` returns a random number.
+The value returned is suitable for use with cryptographic functions such as
+key generation.
+The value is obtained using platform specific cryptographically strong random
+number facilities when available.
+
+== RETURN VALUES
+
+Random number.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+[.text-left]
+xref:nng.7.adoc[nng(7)]
diff --git a/docs/reference/src/api/util/nng_strerror.md b/docs/reference/src/api/util/nng_strerror.md
new file mode 100644
index 00000000..145fd0bc
--- /dev/null
+++ b/docs/reference/src/api/util/nng_strerror.md
@@ -0,0 +1,48 @@
+= nng_strerror(3)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_strerror - return an error description
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+const char * nng_strerror(int err);
+----
+
+== DESCRIPTION
+
+The `nng_strerror()` returns the human-readable description of the
+given error in `err`.
+
+NOTE: The returned error message is provided in US English, but in the
+future locale-specific strings may be presented instead.
+
+NOTE: The specific strings associated with specific error messages are
+subject to change.
+Therefore applications must not depend on the message,
+but may use them verbatim when supplying information to end-users, such
+as in diagnostic messages or log entries.
+
+== RETURN VALUES
+
+This function returns the human-readable error message, terminated
+by a `NUL` byte.
+
+== SEE ALSO
+
+[.text-left]
+xref:libnng.3.adoc[libnng(3)],
+xref:nng.7.adoc[nng(7)]