The advisory line breaking command
will produce a line break if it has no argument or if its optional
argument is 4.
\nolinebreak command is a null command.
\\* commands output a
except inside arrays where the close the current row.
Their optional argument is ignored.
\newline command outputs a
All other line breaking commands, declarations or environments are silently ignored.
They are no pages in the physical sense in html. Thus, all these commands are ignored.