External module in the NCBI Book DTD (and NCBI Collection DTD) that defines chapter-level/part-level metadata elements and textual elements used in such book components
Book-level metadata elements are declared in a separate module, %bookmeta.ent;.
<!ENTITY % bookpart.ent PUBLIC "-//NLM//DTD NCBI Book DTD Book Component Metadata Elements v2.3 20070202//EN" "bookpart.ent" >
bookcustom-modules.ent