This change results from the version 2.0 split of the NCBI Archiving and Publishing DTDs into three DTDs. The restrictions in the phrase-level content models were in place to help regularize the archive. However, they have no place in the more descriptive, open archival DTD that the Archiving (Green) DTD is becoming. The cleanest way to accomplish this change was to relax the fairly clean class/mix structure that the base Suite and the old Archiving DTD used and create one layer of “onion” entities. Thus, individual entities such as %emphasized-text; will continue to exist, but they will contain all the phrase-level elements, through the use of the %all-phrase; Parameter Entity.
<!ENTITY % all-phrase "%address-link.class; | %article-link.class; | %appearance.class; | %emphasis.class; | %inline-display.class; | %inline-math.class; | %math.class; | %phrase.class; | %simple-link.class; | %subsup.class;" >