I have an environment where the customer has defined a number of projects named "Project1", "Project2", "Project3" etc. Each project has a category OID assigned to it and on the user interface we'd like to group all of the projects together in a single list-box. We'd end up with a SPIF that may include the following: <spif:securityCategoryTagSets> <spif:securityCategoryTagSet name="PROJECTS" id="1.1.1.1.0" > <spif:securityCategoryTag name="" tagType="tagType7" tag7Encoding="securityAttributes" minSelection="0" maxSelection="1"> <spif:tagCategory name="Project1" lacv="1" obsolete="false" xml:id="id_project1"></spif:tagCategory> </spif:securityCategoryTag> </spif:securityCategoryTagSet> <spif:securityCategoryTagSet name="PROJECTS" id="1.1.1.1.1" > <spif:securityCategoryTag name="" tagType="tagType7" tag7Encoding="securityAttributes" minSelection="0" maxSelection="1"> <spif:tagCategory name="Project2" lacv="1" obsolete="false" xml:id="id_project2"></spif:tagCategory> </spif:securityCategoryTag> </spif:securityCategoryTagSet> <spif:securityCategoryTagSet name="PROJECTS" id="1.1.1.1.2" > <spif:securityCategoryTag name="" tagType="tagType7" tag7Encoding="securityAttributes" minSelection="0" maxSelection="1"> <spif:tagCategory name="Project3" lacv="1" obsolete="false" xml:id="id_project3"></spif:tagCategory> </spif:securityCategoryTag> </spif:securityCategoryTagSet> </spif:securityCategoryTagSets> However, this will fail the schema check because we don't have unique names for the 'name' attribute on the 'securityCategoryTagSet' ("PROJECTS"). This is what I was going to use to group 'like' categories together on the user interface. I need an attribute that can be used to 'group' similar categories together, the name seemed an easy choice for me and wondered whether the unique constraints could be removed from the schema, or a new 'group' attribute created? Any thoughts? Alan. Alan Borland Technical Architect Boldon James Limited, a QinetiQ company Mobile: +44 (0)7810 556709 Direct: +44 (0)1270 507841 Switch: +44 (0)1270 507800 Email: alan.borland@xxxxxxxxxxxxxxx <mailto:alan.borland@xxxxxxxxxxxxxxx> Web: www.boldonjames.com <x-excid://7DBF0000/pas:x-excid:/7DC00001/jmp:http:/www.boldonjames.com/ >