diff --git a/doc/user/databases.xml b/doc/user/databases.xml
index 12b1617da634e7a008943ca5fbe9609facd3e7d8..2849948c68297348fbb28a8c760d5b4343a40bea 100644
--- a/doc/user/databases.xml
+++ b/doc/user/databases.xml
@@ -1179,7 +1179,7 @@ console.delimiter('')!</programlisting>
         </term>
         <listitem>
             <para>
-             _user is a new system tuple set for support of the authorization feature.
+             _user is a new system tuple set for support of the <link linkend="authentication">authorization feature</link>.
             </para>
         </listitem>
     </varlistentry>
@@ -1201,7 +1201,7 @@ console.delimiter('')!</programlisting>
         </term>
         <listitem>
             <para>
-             _cluster is a new system tuple set for support of the replication feature.
+             _cluster is a new system tuple set for support of the <olink targetptr="replication">replication feature</olink>.
             </para>
         </listitem>
     </varlistentry>
@@ -1499,7 +1499,7 @@ The result will be a table of tuples and will look like this:
 
     <varlistentry>
         <term>
-         <emphasis role="lua">box.space.<replaceable>space-name</replaceable>.index.<replaceable>index-name</replaceable>:min([<replaceable>key</replaceable>])</emphasis>
+         <emphasis role="lua">box.space.<replaceable>space-name</replaceable>.index.<replaceable>index-name</replaceable>:min([<replaceable>key-value</replaceable>])</emphasis>
         </term>
         <listitem>
             <para>
@@ -1507,6 +1507,7 @@ The result will be a table of tuples and will look like this:
             </para>
             <para>
               Returns: (type = tuple) the tuple for the first key in the index.
+              If optional <code>key-value</code> is supplied, returns the first key which is greater than or equal to key-value.
             </para>
             <para>
               Complexity Factors: Index size, Index type.
@@ -1527,7 +1528,7 @@ The result will be a table of tuples and will look like this:
 
     <varlistentry>
         <term>
-         <emphasis role="lua">box.space.<replaceable>space-name</replaceable>.index.<replaceable>index-name</replaceable>:max([<replaceable>key</replaceable>])</emphasis>
+         <emphasis role="lua">box.space.<replaceable>space-name</replaceable>.index.<replaceable>index-name</replaceable>:max([<replaceable>key-value</replaceable>])</emphasis>
         </term>
         <listitem>
             <para>
@@ -1535,6 +1536,7 @@ The result will be a table of tuples and will look like this:
             </para>
             <para>
               Returns: (type = tuple) the tuple for the last key in the index.
+              If optional <code>key-value</code> is supplied, returns the last key which is less than or equal to key-value.
             </para>
             <para>
               Complexity Factors: Index size, Index type.
@@ -2016,7 +2018,8 @@ tarantool&gt; <userinput>t:transform(2,2,'x')</userinput>
               then the result is returned.
             </para>
             <para>
-              Parameters: <code>start-field-number</code> = base 1, may be negative, <code>end-field-number</code> = optional, base 1, negative treated as positive.
+              Parameters: <code>start-field-number</code> = base 1, may be negative, <code>end-field-number</code> = optional, base 1, may be negative.
+              Negative values are counted from the end, for example -2 means the second-last field.
             </para>
             <para>
               Returns: (type = scalar) one or more field values.
diff --git a/doc/user/plugins.xml b/doc/user/plugins.xml
index a9b27010390bd27eee402d5510a3e1d85c68081e..029edf6a38aa0fa88007981aa022b632bff083b8 100644
--- a/doc/user/plugins.xml
+++ b/doc/user/plugins.xml
@@ -63,7 +63,8 @@ on the local host 127.0.0.1.
 </para>
 
 <programlisting>
-# Check that the include subdirectory exists by looking for ~/include/mysql.h.
+# Check that the include subdirectory exists by looking for .../include/mysql.h.
+# (If this fails, there's a chance that it's in .../include/mysql/mysql.h instead.)
 <prompt>$ </prompt><userinput>[ -f ~/mysql-5.5/include/mysql.h ] &amp;&amp; echo "OK" || echo "Error"</userinput>
 OK
 
diff --git a/doc/user/stored-procedures.xml b/doc/user/stored-procedures.xml
index 9f58ec6935064d0668ff76cd9e66cb54a87a6dd1..e675abdeb09367d2da00e65ed6bd0e2a85317680 100644
--- a/doc/user/stored-procedures.xml
+++ b/doc/user/stored-procedures.xml
@@ -629,11 +629,11 @@ tarantool&gt; <userinput>json.decode('{"hello": "world"}').hello</userinput>
             </para>
             <bridgehead renderas="sect4">Example</bridgehead>
 <programlisting>
-<prompt>tarantool&gt;</prompt> <userinput>-- When nil is assigned to a Lua-table field, the field disappears</userinput>
+<prompt>tarantool&gt;</prompt> <userinput>-- When nil is assigned to a Lua-table field, the field is null</userinput>
 <prompt>tarantool&gt;</prompt> <userinput>{nil, 'a', 'b'}</userinput>
----
-- 2: a
-  3: b
+- - null
+  - a
+  - b
 ...
 <prompt>tarantool&gt;</prompt> <userinput> -- When json.NULL is assigned to a Lua-table field, the field is json.NULL</userinput>
 <prompt>tarantool&gt;</prompt> <userinput>{json.NULL, 'a', 'b'}</userinput>