diff --git a/architecture/core.rst b/architecture/core.rst
index fdf67a1..3cd8c32 100644
--- a/architecture/core.rst
+++ b/architecture/core.rst
@@ -977,8 +977,8 @@
 
 Shared memory buffer references manipulated must fit inside one of the
 shared memory areas known from the OP-TEE core. OP-TEE supports two kinds
-of shared memory areas: a mandatory area for contiguous buffers
-an optional extra memory areas for noncontiguous buffers.
+of shared memory areas: an area for contiguous buffers and an area for
+noncontiguous buffers. At least one has to be enabled.
 
 Contiguous shared buffers
 =========================
@@ -1012,6 +1012,10 @@
 Noncontiguous shared memory (also known as dynamic shared memory) is
 enabled with the configuration flag ``CFG_CORE_DYN_SHM=y``.
 
+For performance reasons, the TEE Client Library (``libteec``) uses
+noncontiguous shared memory when available since it avoids copies in some
+situations.
+
 Shared Memory Chunk Allocation
 ==============================
 It is the Linux kernel driver for OP-TEE that is responsible for allocating