BITS 0.2
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| related-object | hr | bold | italic | monospace | overline | overline-start | overline-end
| roman | sans-serif | sc | strike | underline | underline-start | underline-end |
alternatives | inline-graphic | private-char | chem-struct | inline-formula | tex-math
| mml:math | abbrev | index-term | index-term-range-end | milestone-end | milestone-start
| named-content | styled-content | fn | target | xref | sub | sup | x | disp-formula
| disp-formula-group | break | chem-struct-wrap | citation-alternatives | element-citation
| mixed-citation | def-list | list | array | graphic | media | preformat )*
BITS 1.0
( #PCDATA | email | ext-link | uri | inline-supplementary-material | related-article
| related-object | hr | bold | fixed-case | italic | monospace | overline | overline-start
| overline-end | roman | sans-serif | sc | strike | underline | underline-start |
underline-end | ruby | alternatives | inline-graphic | private-char | chem-struct
| inline-formula | tex-math | mml:math | abbrev | index-term | index-term-range-end
| milestone-end | milestone-start | named-content | styled-content | fn | target |
xref | sub | sup | x | disp-formula | disp-formula-group | break | chem-struct-wrap
| citation-alternatives | element-citation | mixed-citation | def-list | list | p
| answer | answer-set | question | question-wrap | array | code | graphic | media
| preformat )*
BITS 2.0
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| related-object | hr | bold | fixed-case | italic | monospace | overline | overline-start
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| underline-end | ruby | alternatives | inline-graphic | private-char | chem-struct
| inline-formula | tex-math | mml:math | abbrev | index-term | index-term-range-end
| milestone-end | milestone-start | named-content | styled-content | fn | target |
xref | sub | sup | x | disp-formula | disp-formula-group | break | chem-struct-wrap
| citation-alternatives | element-citation | mixed-citation | def-list | list | p
| answer | answer-set | explanation | question | question-wrap | question-wrap-group
| array | code | graphic | media | preformat )*
BITS 2.1
( #PCDATA | email | ext-link | uri | inline-supplementary-material | related-article
| related-object | hr | bold | fixed-case | italic | monospace | overline | overline-start
| overline-end | roman | sans-serif | sc | serif | strike | underline | underline-start
| underline-end | ruby | alternatives | inline-graphic | inline-media | private-char
| chem-struct | inline-formula | tex-math | mml:math | abbrev | index-term | index-term-range-end
| milestone-end | milestone-start | named-content | styled-content | fn | target |
xref | sub | sup | x | disp-formula | disp-formula-group | break | chem-struct-wrap
| citation-alternatives | element-citation | mixed-citation | disp-quote | speech
| statement | verse-group | def-list | list | p | answer | answer-set | explanation
| question | question-wrap | question-wrap-group | array | code | graphic | media
| preformat )*