Patrick, There seems to be something wrong with the following expression, but I can't say what. In any case "Matt.1.2" AND "Bible.TEV:Matt.1.2" are not valid with the following. <xs:pattern value="((((\p{L}\p{N})*((\.\p{L}\p{N})*)?):)?(\p{L}\p{N}((\.\p{L}\p{N})* )?))"/> Just any early "bug" report. Todd