BITS 0.2
( title-group?, ( address | alternatives | array | boxed-text | chem-struct-wrap |
fig | fig-group | graphic | media | preformat | supplementary-material | table-wrap
| table-wrap-group | disp-formula | disp-formula-group | def-list | list | tex-math
| mml:math | p | related-article | related-object | ack | disp-quote | speech | statement
| verse-group )*, ( toc-entry | toc-div | x )+ )
BITS 1.0
( title-group?, ( address | alternatives | answer | answer-set | array | boxed-text
| chem-struct-wrap | code | fig | fig-group | graphic | media | preformat | question
| question-wrap | supplementary-material | table-wrap | table-wrap-group | disp-formula
| disp-formula-group | def-list | list | tex-math | mml:math | p | related-article
| related-object | ack | disp-quote | speech | statement | verse-group )*, ( toc-entry
| toc-div | x )+ )
BITS 2.0
( toc-title-group?, ( address | alternatives | answer | answer-set | array | boxed-text
| chem-struct-wrap | code | explanation | fig | fig-group | graphic | media | name-address-wrap
| preformat | question | question-wrap | question-wrap-group | supplementary-material
| table-wrap | table-wrap-group | disp-formula | disp-formula-group | def-list | list
| tex-math | mml:math | p | related-article | related-object | ack | disp-quote |
speech | statement | verse-group )*, ( toc-entry | toc-div | x )+, ( fn-group )* )
BITS 2.1
( sec-meta?, toc-title-group?, ( address | alternatives | answer | answer-set | array
| boxed-text | chem-struct-wrap | code | explanation | fig | fig-group | graphic |
media | name-address-wrap | preformat | question | question-wrap | question-wrap-group
| supplementary-material | table-wrap | table-wrap-group | disp-formula | disp-formula-group
| def-list | list | tex-math | mml:math | p | related-article | related-object | ack
| disp-quote | speech | statement | verse-group )*, ( toc-entry | toc-div | x )+,
( fn-group )* )