If the value of this field is greater than zero, it specifies the
offset from the start of the instance structure. If the value is
- less than zero, it specifies the offset from the *end* of the
+ less than zero, it specifies the offset from the \emph{end} of the
instance structure. A negative offset is more expensive to use, and
should only be used when the instance structure contains a
variable-length part. This is used for example to add an instance