". Otherwise, the dimensions get screwed up. If using the øslidesonly selection, then you also need to enclose the "" command in an allversions* environment. E.g., 
  \begin{allversions*}
    \pagestyle{fancy}
  \end{allversions*}
<style> is the name of the page style, and <header> is the header, and <footer> is the footer. These can only be used for simple page styles that are the same for odd and even pages, and that do not do anything special with section marks. Headers and footers are set in an "" the width of the page (""). You can use stretchable space such as " " or "" to center some information or put it flush against the margins. See the definitions of page styles in "latex.tex" and "article.sty" for examples. Here is an example: Professor Starr wants lots of information in the headers and footers for the slides, and so she defines the page style "mypagestyle":\thedate is set with the \date command. 
  \newpagestyle{mypagestyle}%
    {\sl Big U \hfil \thedate \hfil \thepage}%
    {\hfil File \jobname.tex; printed \today\hfil}
Prof. Starr wants to use the standard "headings" page style for notes and the "mypagestyle" page style for slides, and she wants overlays to just have the overlay number. Therefore, she defines another page style for the overlays: 
  \newpagestyle{myoverlays}{\hfil \thepage}{}
and she puts 
  \pagestyle{headings}
  \slidepagestyle{mypagestyle}
  \overlaypagestyle{myoverlays}
in the preamble. How do I change a parameter only for the slides format? The conditionals
\begin{MD} \ifarticle\ $\ldots$\ ''\else'' $\ldots$\ ''\fi''\\ \ifslidesonly\... ...\ldots$\ ''\fi''\\ \ifportrait\ $\ldots$\ ''\else'' $\ldots$\ ''\fi'' \end{MD}
allow one to select for what versions material is to be processed. "" is true if and only if the "notes" selection is in effect, and so on. The "" clause is optional. See The TEXbook, Chapter 20, for more information about using conditionals. For example, the first line below sets the slide rotation to "right" in the "article" format only. The second line changes the page style for the "notes" and "notesonly" selections and "article" format: 
  \ifarticle\sliderotation{right}\fi
  \ifarticle\ifslidesonly\else\pagestyle{myheadings}\fi\fi
Why does extra space get inserted at the top of a slide when I begin the slide with a color or overlay command (when using the øsemcolor option)? Color and overlay commands with the "semcolor" option use ""'s. TEX adds the space "" between the ""'s and the first material in the slide. Here is the workaround: If that material is an ordinary paragraph, put the command "" just after the color or overlay command. In other cases, if you are sure this is the problem, put "-" just before the color or overlay command.