This is my title page of my thesis and the code is as below
\documentclass{article}
\begin{document}
\hypersetup{
pdftitle={properties of F\textsubscript{2}},
pdfauthor={xxx},
pdfsubject={Masterthesis},
pdfkeywords={Master Thesis},
pdfpagelayout=OneColumn, pdfnewwindow=true, pdfstartview=XYZ, plainpages=false}
\end{document}
I get six warnings as below for using a subscript in this hypersetup environment. Is it the subscript causing the warning or something else? Could someone help me understand this better? Thank you.
Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref) removing '\mathsurround' on input line.
Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref) removing '\z@' on input line.
Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref) removing 'subscript' on input line.
Package hyperref Info: Option 'pdfnewwindow' set 'true' on input line.
Package hyperref Info: Option 'plainpages' set 'false' on input line.