If your translation file translates the English word "at", please check your XSLT files. See problem below. English XSLT contains constructs as: <xsl:call-template name="subfieldSelect"> <xsl:with-param name="codes">at</xsl:with-param> </xsl:call-template> The translated Dutch XSLT contains: <xsl:call-template name="subfieldSelect"> <xsl:with-param name="codes">bij</xsl:with-param> </xsl:call-template> Since at is not a word here, but just two subfields a and t, they should not have been translated of course. Incidentally, bij is the Dutch translation of the English at. The word gets translated and so subfields a and t are replaced by b, i and j. In most cases resulting in no information. Note: Occurs 5 times in MARC21slim2OPACDetail.xsl. And affects display of fields 490/8XX, 773, 780/785.