diff --git a/doc/master/low_memory b/doc/master/low_memory
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+SYNOPSIS
+        void low_memory(int what, int limitvalue, int memory, int reservestate)
+
+DESCRIPTION
+        This efun is called when there is a (potential) low-memory situation.
+        Two different limits for the amount of allocated memory can be
+        configured: a soft limit and a hard limit. If the soft limit is
+        exceeded, the driver calls low_memory() but does nothing else.
+        If the hard limit is exceeded, the driver calls low_memory() as well,
+        but initiates a garbage collection directly after the call. The efun
+        is called as well directly before a user-initiated garbage collection
+        is started.
+
+        <what> denotes the type of limit which was exceeded:
+        - NO_MALLOC_LIMIT_EXCEEDED   (0)
+            No limit was exceeded, but a garbage collection was requested by a
+            call to garbage_collection() and it will begin right after
+            low_memory() returns.
+        - SOFT_MALLOC_LIMIT_EXCEEDED (1)
+            The soft limit was exceeded.
+        - HARD_MALLOC_LIMIT_EXCEEDED (2)
+            The hard limit was exceeded. A garbage collection will begin right
+            after low_memory() returns.
+
+        <limit> specifies the numerical value of the limit which was exceeded.
+        It is 0 in case of NO_MALLOC_LIMIT_EXCEEDED.
+
+        <memory> specifies the amount of allocated memory right now.
+
+        <reservestate> specifies the current state of the memory reserves of
+        the driver. The states of the 3 different reserves are OR'ed together.
+        - USER_RESERVE_AVAILABLE   (1)
+          The user reserve is available.
+        - MASTER_RESERVE_AVAILABLE (2)
+          The master reserve is available.
+        - SYSTEM_RESERVE_AVAILABLE (4)
+          The system reserve is available.
+
+        This efun might be used to inform users about the garbage collection
+        and the expected long lag.
+
+        Another possibility is to initiate a garbage collection deliberately
+        at a suitable time (e.g. during the following night) after the soft
+        limit was hit.
+
+REMARKS
+        If in a low_memory condition when the memory reserves have been used
+        already and they could not be re-allocated after a garbage collection
+        slow_shut_down() is called instead of calling this function again.
+
+HISTORY
+        Introduced in 3.3.719
+
+SEE ALSO
+        debug_info(E), garbage_collection(E), slow_shut_down(M), memory(C)
+        malloc(D)