[Zope] aquisition and refining

Me again (last one for tonight!) Aquisition is groovy, but is it possible to refine aquired properties instead of redefining them from scratch? (Creating a standard_html_header in s subfolder and using <dtml-var standard_html_header> does not produce expected result, that is grabbing the upper-level's definition of standard_html_header). Is there a DTML tag such as <dtml-refine> which, when stated at a given level, would indicate where to insert sublevel redefinition of the DTML method? Maybe i'm thinking too much of OO inheritance... Alex