+=head2 ESCAPE SEQUENCES IN DOUBLE QUOTED ARGUMENTS
+
+In double-quoted arguments (only) use backslash to insert special
+characters:
+
+=over 4
+
+=item C<\a>
+
+Alert (bell) character.
+
+=item C<\b>
+
+Backspace character.
+
+=item C<\f>
+
+Form feed character.
+
+=item C<\n>
+
+Newline character.
+
+=item C<\r>
+
+Carriage return character.
+
+=item C<\t>
+
+Horizontal tab character.
+
+=item C<\v>
+
+Vertical tab character.
+
+=item C<\">
+
+A literal double quote character.
+
+=item C<\ooo>
+
+A character with octal value I<ooo>. There must be precisely 3 octal
+digits (unlike C).
+
+=item C<\xhh>
+
+A character with hex value I<hh>. There must be precisely 2 hex
+digits.
+
+In the current implementation C<\000> and C<\x00> cannot be used
+in strings.
+
+=item C<\\>
+
+A literal backslash character.
+
+=back
+
+=head1 OPTIONAL ARGUMENTS
+
+Some commands take optional arguments. These arguments appear in this
+documentation as C<[argname:..]>. You can use them as in these
+examples:
+
+ add-drive-opts filename
+
+ add-drive-opts filename readonly:true
+
+ add-drive-opts filename format:qcow2 readonly:false
+
+Each optional argument can appear at most once. All optional
+arguments must appear after the required ones.
+
+=head1 NUMBERS
+
+This section applies to all commands which can take integers
+as parameters.
+
+=head2 SIZE SUFFIX
+
+When the command takes a parameter measured in bytes, you can use one
+of the following suffixes to specify kilobytes, megabytes and larger
+sizes:
+
+=over 4
+
+=item B<k> or B<K> or B<KiB>
+
+The size in kilobytes (multiplied by 1024).
+
+=item B<KB>
+
+The size in SI 1000 byte units.
+
+=item B<M> or B<MiB>
+
+The size in megabytes (multiplied by 1048576).
+
+=item B<MB>
+
+The size in SI 1000000 byte units.
+
+=item B<G> or B<GiB>
+
+The size in gigabytes (multiplied by 2**30).
+
+=item B<GB>
+
+The size in SI 10**9 byte units.
+
+=item B<T> or B<TiB>
+
+The size in terabytes (multiplied by 2**40).
+
+=item B<TB>
+
+The size in SI 10**12 byte units.
+
+=item B<P> or B<PiB>
+
+The size in petabytes (multiplied by 2**50).
+
+=item B<PB>
+
+The size in SI 10**15 byte units.
+
+=item B<E> or B<EiB>
+
+The size in exabytes (multiplied by 2**60).
+
+=item B<EB>
+
+The size in SI 10**18 byte units.
+
+=item B<Z> or B<ZiB>
+
+The size in zettabytes (multiplied by 2**70).
+
+=item B<ZB>
+
+The size in SI 10**21 byte units.
+
+=item B<Y> or B<YiB>
+
+The size in yottabytes (multiplied by 2**80).
+
+=item B<YB>
+
+The size in SI 10**24 byte units.
+
+=back
+
+For example:
+
+ truncate-size /file 1G
+
+would truncate the file to 1 gigabyte.
+
+Be careful because a few commands take sizes in kilobytes or megabytes
+(eg. the parameter to L</memsize> is specified in megabytes already).
+Adding a suffix will probably not do what you expect.
+
+=head2 OCTAL AND HEXADECIMAL NUMBERS
+
+For specifying the radix (base) use the C convention: C<0> to prefix
+an octal number or C<0x> to prefix a hexadecimal number. For example:
+
+ 1234 decimal number 1234
+ 02322 octal number, equivalent to decimal 1234
+ 0x4d2 hexadecimal number, equivalent to decimal 1234
+
+When using the C<chmod> command, you almost always want to specify an
+octal number for the mode, and you must prefix it with C<0> (unlike
+the Unix L<chmod(1)> program):
+
+ chmod 0777 /public # OK
+ chmod 777 /public # WRONG! This is mode 777 decimal = 01411 octal.
+
+Commands that return numbers usually print them in decimal, but
+some commands print numbers in other radices (eg. C<umask> prints
+the mode in octal, preceeded by C<0>).
+