<cartographics> is defined as xsd:sequence because <scale> and <projection> are not repeatable, but <coordinates> is repeatable. <all> requires that each element occur zero or one time and would not allow multiple <coordinates> elements. <choice maxOccurs="unbounded"> (which MODS uses in cases without such constraints) would not constrain <scale> and <projection> to maximum one occurence. (Contrast this for example with <subject> ........ <choice maxOccurs="unbounded"> <element name="topic"/> <element name="geographic"/> <element name="temporal"/> <element name="titleInfo"/> etc. </choice> etc. .....any of these subject categories may occur any number of times, including zero, and the whole set may occur in any order.) ----- Original Message ----- From: "Joe Altimus" <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, July 31, 2008 5:30 PM Subject: [MODS] schema use of xsd:sequence to define children of the cartographics element I notice that the MODS schema uses xsd:sequence to define the children of the cartographics element: <xsd:sequence> <xsd:element name="scale" minOccurs="0" type="xsd:string"/> <xsd:element name="projection" minOccurs="0" type="xsd:string"/> <xsd:element name="coordinates" minOccurs="0" maxOccurs="unbounded" type="xsd:string"/> </xsd:sequence> However, an example of <cartographics> in the MODS User Guidelines does not conform to the schema: <subject> <cartographics> <coordinates>E 72°--E 148°/N 13°--N 18°</coordinates> <scale>1:22,000,000</scale> <projection>Conic proj</projection> </cartographics> </subject> so I wonder if the example is wrong or the Schema (xsd:all instead of xsd:sequence)? Is there a strong reason why the children should occur in a rigid order in this case? Joe Altimus Arizona State University Libraries