Back Standard: http://www.w3.org/TR/xslt#disable-output-escaping

<value-of> : disable-output-escaping

Standard excerpt:

An xsl:value-of or xsl:text element may have a disable-output-escaping attribute; the allowed values are yes or no; the default is no; if the value is yes, then a text node generated by instantiating the xsl:value-of or xsl:text element should be output without any escaping.