\texonly
or \htmlonly command. They ignore their argument, if in the
wrong mode, and otherwise simply expand it:
We are now in \texonly{\LaTeX}\htmlonly{HTML}-mode.
In cases such as this you can simplify the notation by using the
\texorhtml command, which has two arguments:
We are now in \texorhtml{\LaTeX}{HTML}-mode.
Another possibility is by prefixing a line with \T or
\W. \T acts like a comment in HTML-mode, and as a noop
in LaTeX-mode, and for \W it is the other way round:
We are now in \T \LaTeX-mode. \W HTML-mode.
The last way of achieving this effect is useful when there are large
chunks of text that you want to skip in one mode--a HTML-document
might skip a section with a detailed mathematical analysis, a
LaTeX-document will not contain a node with lots of hyperlinks to
other documents. This can be done using the iftex and
ifhtml environments:
We are now in
\begin{iftex}
\LaTeX-mode.
\end{iftex}
\begin{ifhtml}
HTML-mode.
\end{ifhtml}
Instead of the iftex environment, you can
also use the tex environment. It is different from iftex only if
you have used \NotSpecial in the preamble.
The environment latexonly has been provided as a service to
latex2html users. Its effect is the same as iftex.