On this element, the global
n attribute indicates the number or other value associated with the line
which follows the point of insertion of this
lb.
Encoders should adopt a clear and consistent policy as to
whether the numbers associated with line breaks relate to the physical
sequence number of the line within the page, or to some aspect of the
logical structure of the text.
By convention,
lb elements should appear at the start of the
line to which they refer.
The
lb tag is intended for making typographic line breaks
in prose. It should be carefully distinguished from the
l
element, used to mark lines of verse.
