You can use the Document Date as a parameter to identify an HTML image by adding it as a KeyValue.
A KeyTypeNum of -6 indicates that the KeyValue represents the Document Date of the target document. The date must be in the form of YYYYMMDD. Separators are optional. For example, February 7, 2009 could be represented as 20090207, 2009/02/07, or 2009-02-07.
The following example shows how an image could be referenced using a document date:
<img alt="mz:101;212:LOGO; -6:20090207; ">