This document describes the proposed XML Schema for XML-Based SMI/ASN.1 Module Representation developed by Michael Kirkham/Muonics. The schema based loosely on the original draft-irtf-nmrg-smi-xml-00.txt DTD by J. Schoenwaelder and F. Strauss. This schema corrects many of the problems in the original DTD (such as lack of specified patterns for various items, misplaced imports, etc.) as well as a greater flexibility in supporting XML as an "input" format (as opposed to only a back-end format generated by a compiler) -or- an output format, and in supporting other types of modules such as the SMI base modules, older SMIv1 modules, and generic ASN.1 modules (though some work remains to be done in the latter area). This schema also adds support for many legally-valid constructs from the SMI, such as "module.descriptor" forms for type and value references, that the original DTD provided no obvious mechanisms for and that many compilers lack support for. The most significant difference that should be noted, other than the above and some different naming conventions, is that this schema uses a flat model (same as with normal non-XML format modules) for describing items with values (such as OBJECT-TYPEs etc.), rather than a heirarchical one with different structures for scalars, tables, rows and columns. The reason for this difference is to allow the format to be used as an "input" or "working" format where not all information may yet be defined/available in order to determine such relationships, as well as to simplify conversion of OIDs from relative to absolute forms using XPath. See the end of this document for a list of revisions. REVISION HISTORY -- Published as version 2.1 -- 05/30/2007 - Corrected 'piberrors' type to be EnumerationList instead of ValueReference to match INSTALL-ERRORS definition and MIB Smithy implementation. 06/07/2004 - Added optional format specifiers for size/range/enumeration values to allow the desired (or source) format of the integer to be indicated. 06/04/2004 - Made ObjectType's access element optional for PIB module compatibility (where only the table has PIB-ACCESS specified). 05/13/2004 - Removed items reserved for SMIng, which was abandoned and isn't showing signs of being restarted. Added support for COPS-PR-SPPI modules. -- Published as version 2.0 -- 07/03/2003 - Bug/typo fixes. SubIdentifier's "value" should be nonNegativeInteger rather than positiveInteger to allow 0. Syntax's "tag" element should be optional. 07/01/2003 - Bug/typo fixes. OIDvalue should be OIDValue. xsd:any should be xsd:anyType. positiveinteger should be positiveInteger. smi:string in DefaultValue should be xsd:string. AgentCapabilities' release attribute must be a simple type. Removed xsd:element and xsd:complexType wrappers around the choice for the various index types in ObjectType, which probably aren't needed. 06/28/2003 - Bug/typo fixes. 'IDETNIFIER' in TypeName, 'xsd:LCIdentifier' in DefaultValue. Deleted SMIv1 status values from ObjectIdent (since OBJECT-IDENTITY doesn't exist in SMIv1, this item can never legally take those values). Deleted reference to ValueReference in IndexList docs, which isn't used there anymore. Description fields are now consistently optional as intended/implemented. 04/26/2003 - Bumped version to 2.0 for more-or-less official release. 04/26/2003 - Added optional 'value' attribute to OIDValue that allows supporting implementations to provide (in addition to the normal 'subid' element form) an absolute OID in order to aid lookups by OID, per request by J. Schoenwaelder and others. 04/26/2003 - Element naming changes for consistency and suggestions from J. Schoenwaelder: exportslist, importslist, typedefslist, macroslist, moduleidentity, objectidentity, rangelist, sizelist and indexlist are now exports, imports, typedefs, macros, moduleid, objectid, ranges, sizes and indices. 04/26/2003 - Added 'pre', 'para' and 'br' element specs to the MixedText type. NOTE: since these are now defined, the default behavior for MixedText is to be wrapped and NOT to be pre-formatted. If you want pre-formatted text, wrap the text in "pre" tags. 04/21/2003 - Deleted obsolete 'type' attribute from objectgroup and notifygroup that was leftover from when these were joined. Added 'module' attribute to 'ASN1Tag' type to split moduleref.valueref format into separate attributes. 04/08/2003 - Added missing 'comments' field to ModuleIdentity structure. Changed 'column' element for CREATION-REQUIRES to ValueReference instead of LCIdentifier. Added 'idlist' DefaultValue for named bits. Added 'implicit' attribute to ASN1Tag and corrected 'value' attribute to point to 'smi:ASN1TagValue' instead of 'xsd:ASN1TagValue'. 04/07/2003 - Corrected 'identifier' DefaultValue choice to allow only lowercase identifiers. Corrected hex string pattern. Changed LCIdentifier/UCIdentifier to be derived from Identifier. 04/06/2003 - Deleted defval element from typedef. 04/05/2003 - Changed imports/exports to importslist/exportslist, and subelements thereof to use attributes. Moved identity element of ModuleDefinition into assignmentslist area (as 'moduleidentity'). This should make looking up the OID for the identity easier by having it in the same place as other OID assignments. Changed some type names to use uppercase characters consitently (e.g. 'LCIdentifier' instead of 'lcidentifier'). Changed 'basetype' to 'typeref'. 12/27/2002 - Added subtype attribute to Syntax complexType, used for single-identifier subtypes (e.g. "SEQUENCE OF SysOREntry"). Changed 'basetype' attribute in Syntax to 'smi:typename' which has a pattern that will except two-part types such as "SEQUENCE OF" or "OCTET STRING". Removed reference element from ModuleIdentity type. Added comments element to Group type. Corrected GroupMembers type to not require a superfluous object element. Corrected GroupsList to allow more than one group. Changed 'modules' to 'module' in ModuleCompliance and AgentCapabilities. (Alternatively, could put all modules under a container element?) 12/22/2002 - Modified to use qualified schema elements (e.g. xsd:complexType vs. complexType), fixed some unqualified smi type references. Added support for ASN.1 tags on types for SMI Base Modules/protocol specs. Added DISPLAY-HINT pattern. Added doctype and XML version headers. 12/20/2002 - Converted to Schema via dtd2xsd.pl and modified/extended with a number of fixes and enhancements by Michael Kirkham. Converted all top-level elements to types, added patterns, added AGENT-CAP support, added misc. SMI Base Module Only features, redefined rules for multiple-module support, altered form for imports, etc.