If an element is used in more than one place, it will be exported with an extra ‘id’ attribute, e.g. <object type="Button" id="id27">. Another reference to that same object will have no content other than an href attribute: <object href="#id27"/>. This reference may come before or after the element’s complete definition. Please note, however, that only known MetaCase namespaces support this (to avoid problems with other schemas) and that nested or cyclic forward references are not supported.

Imports can use the same format: the value of the id attribute is unimportant, but must be unique within the file.

Note also that <slot>, <connection> and <connectionRepr> tags may also have an id attribute, but this is unrelated: slots can never be reused with href. Furthermore, SVG uses its own variant on id/href when referring to gradients. MetaEdit+ ensures uniqueness of gradient ids within an <svg> element, but where multiple <svg> elements occur in a larger document, e.g. in MXS or MXT, the same gradient id numbers will be repeated. MetaEdit+ looks up the correct gradient in these cases.