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The two additions you can make to the default Velocity templates without replacing them are to add HTML markup (actually, Velocity Template Language, which can be a mix of standard HTML markup and Velocity statements) to the <head> section, and/or to add HTML(VTL) markup to the <body> section. You do that by creating one or both of the following files (again relative to idp.home):
views/templates/add-html-head-content.vm
views/templates/add-html-body-content.vm
Examples
Using "add-html-head-content.vm"
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