20.4.3 Formatting browse-link labels
You can provide formatting for Label content wherever you invoke text-link <$_prev> and <$_next> macros. For example:
<p class="navlabel"><$_prev></p>
Button labels are at the mercy of default browser rendering, unless you redefine <$_prev> and <$_next> macros so they include formatting. For buttons, formatting tags must be placed within the <button> tag, surrounding Label text. For example (must be all on one line):
onclick="javascript:location.href='somefile.htm'">
<p class="navlabel">Previous</p></button>
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