HTML5 Paragraphs, Sentences and Phrases

HTML5 Working Group, Greetings.  While HTML5 presently has a document structure granularity of paragraphs, for sentences and phrases in hypertext, options include the <span> element, e.g. <span class="sentence"> and <span class="phrase">, and the use of XML from other XMLNS.  HTML5 markup elements for sentences and phrases are possible.  In any eventuality, sentences and phrases are important CSS3 usage scenarios.
A non-exhaustive list of the benefits of sentences in hypertext include:
 
1. Sentence-level granularity can be of use to the styling, layout and rendering of hypertext. Topics include layout with regard to columns and pages as well as intersentence spacing. Sentence and phrase granularity in documents can facilitate readability, reading speed and comprehension (http://lists.w3.org/Archives/Public/www-style/2012Apr/0153.html).
2. Media overlays in EPUB, based upon SMIL, "text elements' src attributes refer to EPUB Content Document elements by their IDs. The granularity level of the Media Overlay therefore depends on how the EPUB Content Document is marked up. If the finest level of markup is at the paragraph level, then that is the finest possible level at which Media Overlay synchronization can be authored. Likewise, if sub-paragraph markup is available, such as span elements representing phrases or sentences, then finer granularity is possible in the Media Overlay. Finer granularity gives Users more precise results for synchronized playback when navigating by word or phrase and when searching the text, but increases the file size of the Media Overlay Documents." (http://idpf.org/epub/30/spec/epub30-mediaoverlays.html#sec-media-overlays-granularity)
3. Natural language processing of hypertext.  See also: http://en.wikipedia.org/wiki/Sentence_boundary_disambiguation .
4. Navigational.  Sentence elements with IDs can be navigated to and specifically referenced.  See also: http://idpf.org/epub/linking/cfi/epub-cfi.html .
5. Sentence-level granularity of structure can facilitate new semantics including annotational. For example, the epub:type attribute, resembling the role attribute, with some uses indicated at http://idpf.org/epub/vocab/structure/#h_document-text including "concluding-sentence" and "topic-sentence".
6. Speech synthesis.  SSML includes paragraphs and sentences (http://www.w3.org/TR/speech-synthesis11/#S3.1.8.1).  Sentence granularity can enhance the audio output of synthesis processors processing hypertext. A non-exhaustive list of the benefits of phrases in hypertext include: 1. Phrase-level granularity can be of use to styling, layout and rendering. Topics include text wrapping. Sentence and phrase granularity in documents can facilitate readability, reading speed and comprehension (http://lists.w3.org/Archives/Public/www-style/2012Apr/0153.html).2. Media overlays in EPUB, based upon SMIL, "text elements' src attributes refer to EPUB Content Document elements by their IDs. The granularity level of the Media Overlay therefore depends on how the EPUB Content Document is marked up. If the finest level of markup is at the paragraph level, then that is the finest possible level at which Media Overlay synchronization can be authored. Likewise, if sub-paragraph markup is available, such as span elements representing phrases or sentences, then finer granularity is possible in the Media Overlay. Finer granularity gives Users more precise results for synchronized playback when navigating by word or phrase and when searching the text, but increases the file size of the Media Overlay Documents." (http://idpf.org/epub/30/spec/epub30-mediaoverlays.html#sec-media-overlays-granularity)
3. Natural language processing of hypertext.4. Phrase-level granularity of structure can facilitate new semantics including annotational. For example, the epub:type attribute, resembling the role attribute, with some uses indicated at http://idpf.org/epub/vocab/structure/#h_document-text including "keyword".
5. Speech synthesis. For example, pauses between words may differ inside and between phrase elements.
 
Kind regards,
 
Adam Sobieski