XML for Justice


Gae Lyn DeLand, the IT Director in Corrections sent me a note about the Department of Justice's XML standards initiative.  The page includes a large (332 pages) and comprehensive Justice and Public Safety XML Data Element Definitions document which I found to be sobering because of its size and complexity.  The document includes a set of general principles which I think are worth reviewing and included in any such effort:

  • Any XML specification developed should be guided by the principles put forth by the World Wide Web Consortium (w3c)
  • Internal system representation is not constrained by these guiding principles or the associated data element definitions. The information contained in these documents simply provides a baseline for exchange of information.
  • XML Specifications shall be over-inclusive by specifying those elements that may be required by fewer than all participants and making those elements optional.
  • XML Specifications shall be extensible.
  • Wherever possible, previously developed solutions should be adopted or extended.
  • International implications of XML specifications should be considered, and international standards shall be used as guides where possible.
  • XML specifications shall be broad enough to accommodate jurisdictional differences.
  • When operational requirements dictate differences in specificity, mapping from the more specific elements to the less specific elements shall be made available.
  • It is the responsibility of each group to insure that all system-specific features are removed prior to transmission to another group.
  • Data elements may contain other elements and may even be recursive.
  • Certain complex elements are sufficiently independent and driven by group business rules such that they cannot be used by more that one organization. In such cases the shareable simple elements contained within the complex element are defined.
  • For every element, a default minimum attribute set will be available for use. These attribute(s) will, for the most part be optional. However, in specific instances (clearly noted in the Data Element Dictionary) they may be required or have default values.
  • Data element content length generally will not be restricted in the Data Element Dictionary. However, there may be some elements for which a maxLength parameter is specified. Further, specific implementations can incorporate maxLength-type parameters for other elements into their schema for validation purposes.
  • Generic tag names within complex elements are preferred when the data is clearly the same entity (e.g., state may be used to refer to both the state of the postal address and the state of vehicle registration). Generic tag names should be avoided when the meaning is ambiguous (e.g., number should not be used to represent both a phone number and an operator license number; explicit tag names should be used).

One of the areas that I think NASCIO (still on my mind) could offer more assitance to states is by helping to sort out the various XML standards that are being developed and even intaking the lead in developing XML standards in areas where nothing is happening.