The @when attribute cannot be used with any other att.datable.w3c attributes. The @from and @notBefore attributes cannot be used together. The @to and @notAfter attributes cannot be used together. @calendar indicates the system or calendar to which the date represented by the content of this element belongs, but this element has no textual content. The @unit attribute may be unnecessary when @unitRef is present. The element should not be categorized in detail with @subtype unless also categorized in general with @type @targetLang should only be used on if @target is specified. The element indicated by @spanTo () must follow the current element @schemeVersion can only be used if @scheme is specified. Abstract model violation: Paragraphs may not occur inside other paragraphs or ab elements. Abstract model violation: Lines may not contain higher-level structural elements such as div, p, or ab. Information about a deprecation should only be present in a specification element that is being deprecated: that is, only an element that has a @validUntil attribute should have a child <desc type="deprecationInfo">. Only one of the attributes @target and @cRef may be supplied on . Only one of the attributes @target' and @cRef' may be supplied on The content of a "gloss" list should include a sequence of one or more pairs of a label element followed by an item element If the @target attribute on is used, the relatedItem element must be empty A relatedItem element should have either a 'target' attribute or a child element to indicate the related bibliographic item Abstract model violation: Lines may not contain lines or lg elements. An lg element must contain at least one child l, lg, or gap element. Abstract model violation: Lines may not contain line groups. On , either the @marks attribute should be used, or a paragraph of description provided You must supply at least two values for @target or on Abstract model violation: ab may not occur inside paragraphs or other ab elements. Abstract model violation: Lines may not contain higher-level divisions such as p or ab. You must supply at least two values for @target on Abstract model violation: Lines may not contain higher-level structural elements such as div. Abstract model violation: p and ab may not contain higher-level structural elements such as div. One of the attributes 'name', 'ref' or 'key' must be supplied Only one of the attributes @active and @mutual may be supplied the attribute 'passive' may be supplied only if the attribute 'active' is supplied An objectIdentifier must contain at minimum a single piece of locating or identifying information. The first and last elements of this path are the same. To specify a closed polygon, use the zone element rather than the path element. The @spanTo attribute of is required. The @spanTo attribute of is required. The @spanTo attribute of is required. must have at least one child add and at least one child del The element should not be used outside of msDesc. The element may appear once only The element may appear once only The element may appear once only The element should not be used outside of msDesc. The element should not be used outside of msDesc. An msIdentifier must contain either a repository or location.