STMML defines a number of data types suited to STM. It also defines a number of complex data strucures such as arrays, matrices and tables. the constraints are sometimes created through elements and sometimes through attributes. We classify the general components as follows:

Abstract Data Structures

• scalar. A scalar quantity, expressible as a string, but with many optional facets such as errors, units, ranges, etc. Most elements may have countType attribute to indicate more than one instance.
• array. An array of homogeneous scalars whose size is described by sizeType. Delimiters in string representations can ve varied.
• matrix. A rectangular (often square) matrix of homogeneous scalars. Many matrices have special functions (see matrixType) such as geometric transformations
• table. An table where the columns are homogeneous arrays.
• list. A list of heterogeneous components from any namespace.
• sizeType. Size of arrays
• delimiterType. A lexical delimiter

Links and References

• link. Support for simple hyperlinks and link structures
• refType. A reference to an element
• namespaceRefType. A reference to an element, including namespace-like prefixes

Data-based simpleTypes

• coordinate2Type. A 2-D coordinate
• coordinate3Type. A 3-D coordinate
• dataTypeType. An enumeration of data types (similar to those in XML Schema).
• errorBasisType. Basis of numeric error estimates
• minType. Minimum value
• maxType. Maximum value

Common attribute types

• idType. Specifies lexical patterns for IDs
• id. ID attribute (highly encouraged)
• title. Title attribute (highly encouraged)
• conv. Convention attribute