Page markings in Revtex 4

Question

How do I add page markings to specific pages, in Revtex 4?

And, how do I wrap long page markings?

Specifically, I need to add a sentence, "This page may contain proprietary information ...." on each of a range of pages.

Here is a partial example with all of the packages that I am using in the document.

The text inside of the markboth, needs to be wrapped.

\documentclass[pra,11pt,nofootinbib]{revtex4}
\usepackage{amsmath}    % need for subequations
\usepackage{amssymb}    % need for subequations
\usepackage{graphicx}   % need for figures
\usepackage{subfigure}  % use for side-by-side figures
\usepackage{enumitem}

\usepackage{placeins}
\usepackage{makecell}
\usepackage{framed}
\usepackage{changebar}

\pagestyle{myheadings}

\begin{document}

\section{Introduction}
Some text, blah blas

\label{firstsecret}

\markboth{}{May contain trade secrets or commercial or financial information that is privileged or confidential and exempt from public disclosure.}

Here goes some big secret, more blah blah


\label{laststsecret}

\end{document}

Answer 1

One solution appears to be to use the fancyhdr package, as follows.

For the preamble we can use this to establish a plain-like pagestyle, with pagenumbers in the upper right.

\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\renewcommand{\headrulewidth}{0pt}
\rhead{\thepage}

Then to add text to the center position of the header on the current page, with line wrap,

\chead{Long sentence with line wrap here\\ followed by the rest of the sentence.}

And we can reset everything and go back to numbers only, with

\fancyhf{}
\renewcommand{\headrulewidth}{0pt}
\rhead{\thepage}

Caveat, some care needs to be applied with respect to where the lines are inserted and take effect.