The model for a section-like structure that may or may not have an initial title
<!ENTITY % sec-opt-title-model "(title?, (%para-level;)*, (%sec-level;)* )" >
(title?, (boxed-text | chem-struct-wrap | fig | graphic | media | preformat | supplementary-material | table-wrap | disp-formula | disp-formula-group | p | def-list | list | disp-quote | speech | statement | verse-group)*, (sec)* )
JATS-articleauthcustom-models0.ent